When a part contains an internal spline, keyway, internal gear, square hole, or another formed profile, 밀링, slotting, 와이어 방전 가공, and broaching may all appear to be possible options. However, when the project calls for consistent dimensions, short cycle times, and repeat production, broaching often becomes the more practical choice.
Broaching is especially well suited to medium- and high-volume production, but it is not limited to mass production. For a difficult profile, a tight-tolerance internal feature, or a part that is expensive to machine by other methods, broaching may also make sense at lower quantities. The key is to evaluate the part geometry, material, heat-treatment condition, tolerance, and expected production volume together.
What Is Broaching in Metalworking?
Broaching is a machining process in which a multi-tooth cutting tool, called a broach, is pushed or pulled through or across a workpiece. Each successive tooth is slightly larger than the one before it, so the cutting allowance is removed layer by layer as the tool travels in a straight line.
The difference in height or width between successive teeth is called the rise per tooth. Because the feed is built into the tool itself, a broaching machine normally needs only one primary motion. Roughing, semi-finishing, finishing, and sizing can all be completed during a single working stroke.
That is why broaching can be both fast and accurate. Once the broach, workholding, and process parameters have been established, the same profile can be repeated from part to part with limited operator influence.
What Features Can Be Broached?
Round, square, rectangular, hexagonal, polygonal, and specially shaped through-holes
Straight-sided, involute, serrated, and special internal splines
Internal and external keyways
Internal gears, external gears, racks, and partial-tooth profiles
Flat surfaces, slots, grooves, dovetails, and formed external surfaces
Fir-tree and dovetail root forms for turbine and compressor components
Combined profiles that integrate a bore, spline, keyway, chamfer, or sizing feature in one tool
For conventional linear broaching, the surfaces being cut generally need to remain parallel to the direction of tool travel. Internal broaching also requires a starter hole large enough for the broach pilot to enter and for chips to be carried through the cut.
Is Your Part Suitable for Broaching?
A broached part does not have to be simple, but its geometry must allow the tool to enter, cut, carry chips, and exit without interference. The following points provide a practical first check.
| Design item | What to check |
| Feature access | A conventional internal broach needs a through-hole or another clear path for the tool to enter and exit. |
| Profile direction | The surfaces to be generated should normally be parallel to the direction of broach travel. |
| Starter hole | The pilot must enter freely, and the hole should have adequate size, roundness, straightness, and position. |
| Part length | The broached length must remain within the broach’s chip-space and strength limits. |
| 벽 두께 | Thin or uneven walls can expand during cutting and spring back after the broach passes. |
| Datum face | The supporting face should be flat and square to the starter hole unless a self-aligning support is used. |
| Material and hardness | Machinability, heat-treatment condition, local hard spots, and hardness variation affect tool life and surface finish. |
| 공차 | Size, profile, pitch, runout, and surface-finish requirements should be defined separately instead of relying on one general tolerance. |
| 생산량 | A dedicated broach becomes more economical as repeat quantity and annual demand increase. |
Blind holes, stepped holes, deep obstructed features, and profiles that change along the cutting direction are generally poor candidates for conventional broaching. Rotary broaching or another machining method may still be possible, depending on the depth and geometry.
If there is uncertainty, a supplier should review the 2D drawing and 3D model before the process is fixed. Small changes to the entry chamfer, bottom hole, wall thickness, datum scheme, or tolerance can greatly reduce tooling risk and cost.
How Is the Broaching Process Performed?
A broach is not simply a row of identical cutting teeth. Its sections guide the tool, remove the allowance in stages, establish the final size, and support the tool as it leaves the part.
Shank and neck: connect the broach to the machine and transmit the pulling or pushing force.
Front pilot: enters the prepared hole and aligns the broach with the workpiece before cutting begins.
Roughing, semi-finishing, and finishing teeth: remove the machining allowance progressively and generate the required profile.
Sizing teeth and rear pilot: stabilize the final size and finish, support the broach, and protect the completed surface as the tool exits.
Review the drawing, material, heat treatment, tolerance, surface finish, and production quantity.
Prepare the starter hole, datum face, and entry or exit chamfer required for the broach and fixture.
Select or manufacture the broach, and verify the machine stroke, pulling force, speed range, and tool connection.
Locate and support the workpiece so the starter hole is aligned with the broach travel direction.
Apply the specified cutting fluid, then pull or push the broach through the workpiece in one controlled stroke.
Remove chips from the tooth gullets, clean the workpiece, and inspect the first part before production continues.
Monitor size, surface condition, cutting force, and tool wear throughout the production run.
Workholding and lubrication are critical. The fixture must support the cutting load without distorting the part, while the cutting fluid must reach the cutting zone, reduce friction, and carry chips away. Internal broaching and horizontal broaching usually make fluid delivery and chip evacuation more difficult than open external or vertical operations.
What Are the Main Types of Broaching?
Broaching can be classified by the surface being machined, the direction of force, the tool arrangement, and the condition of the workpiece. Each type solves a different production problem.
Internal Broaching
Internal broaching produces a feature inside a prepared opening. Typical examples include round and polygonal holes, keyways, internal splines, and internal gears. A starter hole is required so the front pilot and cutting teeth can pass through the part.
External and Surface Broaching
External broaching removes material from an open surface to produce flats, slots, grooves, formed faces, external teeth, or blade-root profiles. The workpiece and tool require rigid guidance because the cut is not self-centered by a surrounding bore.
Keyway Broaching
Keyway broaching uses a keyway broach with a guide bushing or horn to produce a straight internal keyway. Shims may be added in successive passes when the full keyway depth cannot be cut safely in one pass. It is a common, economical option for standard bores and key sizes.
Spline Broaching
Spline broaching forms multiple teeth or grooves around a bore in one stroke. It is used for straight-sided, involute, serrated, and special splines in gears, hubs, couplings, transmission parts, and steering components. The broach can also size the minor diameter when the drawing requires it.
Pull Broaching
In pull broaching, the machine draws the broach through the workpiece. The tool is loaded mainly in tension, so it can be longer and carry more teeth than a comparable push broach. This arrangement is widely used for internal profiles and high-volume production.
Push Broaching
In push broaching, the tool is pressed through the workpiece and is therefore loaded in compression. The broach must be shorter and well guided to limit bending or buckling. Push broaching is often used for short keyways, small holes, repair work, and manual or low-volume operations.
Rotary Broaching
Rotary broaching, also called wobble broaching, uses a slightly angled tool that rotates relative to the workpiece. It can form small square, hexagonal, and other polygonal profiles on a lathe, machining center, or screw machine. It is useful for short features and some blind holes, but it is not the same as conventional linear broaching.
Pot Broaching
Pot broaching uses an annular tool assembly with inward-facing teeth. The workpiece is pushed or pulled through the tool to generate an external spline, gear, or similar circumferential profile. It is generally selected for repeat production of shafts and other external toothed parts.
Hard Broaching
Hard broaching finishes a previously soft-broached internal spline after heat treatment. A carbide broach removes heat-treatment distortion from a workpiece that may be approximately 45–65 HRC, improving tooth form, pitch accuracy, effective space width, runout, and surface finish. It requires a rigid machine, controlled stock allowance, accurate pre-broach sorting, and specialized tooling.
What Materials Are Broaches Made From?
Broach material is selected according to the workpiece material, hardness, cutting speed, profile complexity, expected tool life, and whether the tool must be reground and recoated.
| Broach material | 일반적인 사용 | Main considerations |
| Conventional high-speed steel | General steels, cast iron, and nonferrous materials at moderate speed | Good toughness, practical to manufacture and regrind, and widely used for conventional broaching |
| Cobalt high-speed steel | Alloy steel, stainless steel, and workpieces that generate more heat | Higher hot hardness and wear resistance than conventional HSS |
| Powder metallurgy high-speed steel | Demanding profiles and longer production runs | Fine, uniform structure with a useful balance of toughness, edge strength, and wear resistance |
| 초경 | Hard broaching, abrasive materials, and high-speed production | High wear resistance but lower impact toughness; requires a rigid machine and stable process |
| Built-up or modular construction | Large, expensive, or replaceable cutting sections | Allows a steel body to carry HSS or carbide cutting elements and can simplify repair or replacement |
M2 is common for general-purpose broaches, while M35 or M42 may be selected when greater hot hardness or wear resistance is needed. The exact grade should be based on cutting tests and the workpiece condition rather than on the material name alone.
Coatings such as TiN, TiCN, 알크론, or application-specific coatings can reduce friction and wear. A coating cannot compensate for incorrect tooth geometry, poor chip space, excessive rise per tooth, misalignment, or inadequate lubrication. Regrinding and recoating must therefore be managed as one controlled tooling process.
What Equipment Is Required for Broaching?
A broaching system normally includes the machine, broach, workholding, tool connection and guidance, cutting-fluid system, chip handling, guarding, and inspection equipment. The correct machine depends on the cutting direction, stroke, force, part size, and automation target.
| Equipment type | Typical application | Key characteristics |
| Horizontal broaching machine | Long internal broaches and general pull broaching | Easy tool access and installation, but requires more floor space and careful chip removal |
| Vertical broaching machine | Internal, surface, and automated production | Compact footprint; may pull down, pull up, or raise the worktable along the broach |
| Hydraulic broaching machine | General-purpose and high-force production | Smooth controllable motion and large pulling force; requires hydraulic-fluid and system maintenance |
| Servo-driven broaching machine | Precision production and process monitoring | Programmable speed and position, stable force control, lower energy use, and easier data collection |
| Surface broaching machine | Flats, slots, cast surfaces, and formed external profiles | Rigid tool slide and dedicated fixtures support broad external cuts |
| Continuous broaching machine | Very high-volume surface production | Workpieces move continuously past stationary or circulating tools |
| Hard broaching machine | Heat-treated internal splines and other hardened profiles | High rigidity, accurate alignment, force monitoring, and carbide-tool capability |
| CNC rotary broaching attachment | Short polygonal holes on CNC lathes or machining centers | Compact solution for rotary broaching without a dedicated linear broaching machine |
Horizontal and vertical describe the machine layout, while hydraulic and servo describe the drive system. They are not competing categories: a vertical machine, for example, may use either hydraulic or servo drive. The choice should be based on force, stroke, precision, cycle time, maintenance, floor space, and automation requirements.
Which Parts Are Suitable for Manual Broaching?
Manual broaching is mainly used for short keyways, small square or polygonal holes, repair work, prototypes, and low-volume parts. A standard push broach, guide bushing, shim set, and arbor press can often complete these features without a dedicated production broaching machine.
The setup must remain square and rigid. Because a push broach works in compression, uneven force, excessive tool length, poor alignment, or press deflection can bend or break the tool. Pulling a suitably designed broach can reduce buckling risk, but the broach and connection must be engineered for tensile loading.
Manual broaching should not be treated as an uncontrolled shop-floor shortcut. The press capacity, tool guidance, guards, cutting fluid, chip removal, and operator safety all need to be checked, especially when the required force is high or the tool is custom-made.
Which Parts and Industries Use Broaching?
Broaching is used wherever a formed feature must be repeated accurately and quickly. It is particularly valuable when the feature would otherwise require several machining operations or repeated indexing.
Automotive Drivetrain Parts
Typical applications include transmission gears, differential bevel gears, hubs, synchronizer sleeves, parking gears, output components, steering racks, couplings, and drive shafts. Internal splines and keyways are often soft-broached before heat treatment, while parts with tighter post-heat-treatment requirements may receive hard broaching.
Aerospace and Energy Components
Broaching is used for turbine and compressor blade-root slots, fir-tree profiles, dovetails, disk slots, and other high-integrity formed surfaces. These parts demand rigid equipment, carefully controlled tool geometry, stable material condition, and full inspection and traceability.
Industrial Machinery Parts
Gears, pulleys, sprockets, couplings, bushings, valve parts, pump components, machine-tool parts, connecting links, and hydraulic components may all contain broached bores, keyways, splines, teeth, flats, or special profiles. Broaching can combine several features in one stroke when a repeatable production requirement justifies the tooling.
Agricultural Machinery Parts
Agricultural equipment places heavy loads on shafts, hubs, gears, and couplings, so reliable torque transmission and part interchangeability are important. Broaching is used for splines, keyways, square holes, serrations, and formed drive features in tractors, tillers, cultivators, plows, harrows, seeders, planters, sprayers, spreaders, balers, mowers, forage harvesters, combine harvesters, grain conveyors, augers, loaders, manure spreaders, feed mixers, and related implements. The same process is also used for smaller service parts and wear components when a standard, repeatable fit is required.
Which Workpiece Materials Are Suitable for Broaching?
Many ferrous and nonferrous materials can be broached, but each material requires a suitable tooth geometry, rise per tooth, cutting speed, cutting fluid, and tool material.
| Workpiece material | Broaching behavior | Process focus |
| Carbon and alloy steel | Widely broached in normalized, annealed, or quenched-and-tempered condition | Control hardness, microstructure, built-up edge, and heat-treatment sequence |
| 스테인리스강 | Tough, prone to work hardening, and demanding on the cutting edge | Use sharp geometry, adequate rise per tooth, strong lubrication, and wear-resistant tool material |
| 주철 | Generally machinable but may contain abrasive inclusions or hard spots | Select suitable tool material and prevent local defects from chipping the teeth |
| 알루미늄 합금 | Low cutting force but some grades can form long chips or built-up edge | Use sharp teeth, smooth gullets, correct lubrication, and effective chip removal |
| 황동 및 청동 | Often produce good size and finish when geometry is matched to the alloy | Avoid grabbing, rubbing, and unsuitable cutting-fluid selection |
| Heat-treated steel | Conventional HSS broaching becomes difficult as hardness rises | Use controlled pre-broach allowance and a carbide hard-broaching process where required |
For conventional soft broaching, uniform hardness is often more important than a single nominal hardness value. Very soft, gummy material can tear or form a built-up edge, while excessive hardness or isolated hard spots can shorten tool life or cause tooth chipping. Material certificates and heat-treatment records therefore matter.
What Accuracy and Surface Finish Can Broaching Achieve?
Broaching is selected for its repeatability as much as for its speed. Under stable conditions, conventional internal broaching can commonly hold approximately IT7–IT8 dimensional accuracy, while an optimized precision process may achieve tighter results. The practical tolerance depends on profile size, broached length, wall thickness, workpiece material, tool condition, fixture, and inspection method.
Surface roughness values around Ra 0.4–1.6 µm are achievable on many well-controlled applications, although the specified value should reflect the function of the part. A broader result may be appropriate for rough external broaching, difficult materials, or profiles in which side edges rub rather than cut freely.
For splines and gears, a single bore size is not enough to define quality. Pitch error, accumulated pitch deviation, profile deviation, lead deviation, effective space width, actual space width, major and minor diameters, measurement over pins, and runout may all need separate control.
Broaching Cannot Correct Starter-Hole Position
Like reaming, internal broaching generally follows the prepared hole. It can improve size, form, and surface finish, but it cannot reliably move a hole to a new theoretical position. If the starter hole is off-center, tilted, curved, or not square to the supporting face, the broached feature may retain or magnify that positional error.
The starter hole, datum face, and fixture must therefore be produced and inspected as part of the broaching process. A spherical support can allow limited self-alignment when appropriate, but it does not replace sound datum design and hole preparation.
How Should a Broached Part Be Designed for Manufacturability?
Most broaching problems are easier to prevent in the drawing than to correct at the machine. The following five design points have the greatest influence on feasibility, tooling risk, and unit cost.
1. Prefer a Through Feature
A clear entry and exit path allows the broach to pass through the part and carry chips out of the cut. If a blind feature is unavoidable, confirm whether rotary broaching, slotting, EDM, or another process is more suitable before the geometry is released.
2. Provide a Suitable Starter Hole and Edge Condition
The starter hole must accept the front pilot without forcing and should provide a consistent cutting allowance around the profile. Entry and exit edges should include the chamfer or relief needed to prevent burrs, impact loading, and interference with the tool.
3. Control Wall Thickness and Part Rigidity
Thin, interrupted, or uneven walls can deform under radial cutting force and spring back after the tool passes. Add support where possible, maintain balanced wall thickness, and avoid locating clamps where they will distort the finished feature.
4. Define Datums and Tolerances Clearly
Identify which face locates the part during broaching and which surfaces are functionally related to the broached profile. Specify size, profile, position, runout, and surface finish only as tightly as the assembly requires, because every unnecessary requirement can increase tooling, inspection, and scrap risk.
5. Establish Heat Treatment and Spline Requirements
State whether the feature is inspected before or after heat treatment, and provide final hardness, effective case depth, and any allowed pre-broach or hard-broach stock. For splines, include the applicable standard, tooth count, pressure angle, module or diametral pitch, class, major and minor diameters, space-width requirements, and gauge criteria.
| Design item | Preferred approach |
| Tool path | Provide a straight, unobstructed entry and exit path aligned with the profile. |
| Starter hole and edges | Control hole geometry and provide the entry chamfer, exit relief, and deburring access required by the process. |
| Part support | Use a stable datum face, adequate wall thickness, and fixture access that will not distort the part. |
| Functional requirements | Separate size, profile, position, runout, finish, heat treatment, and inspection requirements. |
| Production planning | Provide annual volume and program life so the tool design, machine, automation, and spare-tool plan can be evaluated together. |
How Does Broaching Compare with Other Machining Methods?
| 공정 | Best suited to | Main trade-off |
| Broaching | Repeat internal or external profiles requiring high output and consistent geometry | Dedicated tooling and clear tool travel are normally required |
| Slotting or shaping | Low-volume keyways, internal teeth, repair work, and flexible geometry | Longer cycle time and greater dependence on machine setup |
| 밀링 | Open profiles, prototypes, and parts requiring frequent design changes | Internal access and small corner radii may be limited |
| 와이어 EDM | Hard materials, sharp internal corners, and low-volume precision profiles | Slow cutting and a required through-path for the wire |
| Sinker EDM | Blind cavities and difficult internal geometry in conductive materials | Electrode cost, slower cycle time, and recast-layer considerations |
| Rotary broaching | Short polygonal holes on lathes or machining centers | Depth, size, profile, and machine-load limits are more restrictive than linear broaching |
The lowest tooling price is not always the lowest production cost. For a recurring spline or keyway, broaching may require a larger initial investment but deliver a much shorter cycle time and more consistent parts. For prototypes or frequent design changes, a flexible process such as slotting, milling, or EDM may be more economical.
What Factors Affect Broaching Cost?
A broaching quote includes more than machine time. Tool design, manufacturing, fixture development, setup, expected tool life, regrinding, inspection, and production volume all contribute to the final unit cost.
| 비용 요소 | Why it matters | Possible way to reduce cost |
| Profile complexity | Complex forms require more design work, tighter broach manufacturing, and specialized inspection | Simplify nonfunctional corners, reliefs, or combined features where possible |
| Feature size and length | Long or large profiles increase cutting force, tool length, chip space, and machine requirements | Keep the broached length and stock allowance only as large as functionally necessary |
| Material and hardness | Tough, abrasive, work-hardening, or hardened materials reduce tool life | Control material condition and define the heat-treatment sequence early |
| Tolerance and finish | Tighter requirements increase tool accuracy, process control, inspection, and scrap exposure | Use function-based tolerances and identify critical characteristics |
| Broach construction | Solid, sectional, built-up, HSS, carbide, and coated tools have different purchase and lifecycle costs | Evaluate purchase price together with regrinding, recoating, and replacement strategy |
| Production quantity | Low quantity carries more of the dedicated tooling and setup cost per part | Provide realistic annual and lifetime volumes for cost amortization |
| Automation and inspection | Loading, chip removal, in-process monitoring, gauges, and traceability add investment but reduce labor and variation | Match the automation and inspection level to production risk and volume |
For a repeat program, the broach should be treated as a production asset rather than a consumable purchased only on initial price. Tool life per grind, number of possible regrinds, coating cycles, repair options, spare-tool inventory, and lead time all affect total cost.
An accurate quotation therefore requires both the part data and the production plan. Quoting from a profile size alone can hide major differences in material, hardness, broached length, datum control, gauge requirements, and expected annual volume.
Common Broaching Defects and Quality Control
| Defect | Common causes | Control measures |
| Scale-like tearing or rough surface | Built-up edge, unsuitable speed, excessive rise per tooth, dull teeth, poor material condition, or weak lubrication | Optimize speed and rise per tooth, keep the edge sharp, control hardness, and use a suitable lubricating cutting fluid |
| Irregular scratches | Chips or built-up edge on the cutting teeth, rough gullets, or damaged edges | Clean after every stroke, polish or regrind damaged areas, and keep the chip gullets smooth |
| Continuous longitudinal marks | Chipped sizing teeth or raised damage on the rear pilot | Protect the broach during handling and storage; stone or regrind damaged areas before use |
| Circumferential waviness | Periodic changes in cutting force, too few teeth in cut, machine vibration, or inconsistent tooth geometry | Increase process stability, optimize tooth pitch and rise per tooth, and verify machine and tool rigidity |
| Oversize or undersize bore | Grinding burrs, tool wear, elastic recovery, thin walls, thermal effects, or incorrect sizing-tooth dimensions | Qualify a reground broach, control tool dimensions, support the part, and establish compensation through trials |
| Profile or position error | Misalignment, poor starter-hole geometry, dirty datum faces, uneven material hardness, or one-sided fluid delivery | Control the starter hole and datum, clean the setup, align the tool, and distribute cutting fluid evenly |
| Tooth chipping or broach breakage | Insufficient chip space, excessive force, hard spots, incorrect heat treatment, tool bending, poor installation, or chips left in the gullets | Verify force and chip capacity, inspect material and tool condition, maintain alignment, and never force a stalled broach |
Broach Life and Regrinding Management
Each broach should have a tool record covering the part number, tool sequence, issue date, parts produced, accumulated quantity, regrinds, coating history, inspection results, and abnormal events. Regrinding should remove the minimum material needed to restore a sharp edge while preserving the designed rake angle, rise per tooth, tooth form, and gullet geometry.
Production Process Monitoring
Cutting force, cycle time, surface appearance, chip shape, dimensional trend, fluid condition, and unusual vibration or noise should be monitored. A sudden force increase or deteriorating finish can indicate a dull edge, packed chips, misalignment, material variation, or insufficient lubrication before a major failure occurs.
Inspection and Quality Traceability
Inspection should match the functional requirement. Depending on the part, this may include bore gauges, coordinate measurement, profile inspection, measurement over pins, spline GO and NO-GO gauges, runout inspection, surface-roughness testing, hardness verification, and case-depth records. First-article and in-process results should be linked to the broach, machine, production lot, and heat-treatment batch.
How Do You Select a Reliable Broaching Supplier?
A capable supplier should be able to evaluate the entire manufacturing chain, not merely place a part on an available machine. The following points are worth checking before tooling is released.
Experience with the required profile, material, hardness, tolerance, and production volume
Suitable horizontal, vertical, hydraulic, servo, surface, rotary, or hard-broaching equipment
Broach design, manufacturing, inspection, regrinding, recoating, and spare-tool support
Fixture design and DFM capability for the starter hole, datums, wall thickness, and part support
A defined cutting-fluid, chip-control, tool-cleaning, and preventive-maintenance process
Inspection capability for size, form, spline or gear parameters, runout, finish, hardness, and traceability
Clear first-article approval, process-change control, delivery planning, and response to tool damage or quality problems
For an ongoing program, ask how the supplier will maintain output while a broach is being reground or repaired. Spare tooling, qualified backup equipment, documented setup data, and a realistic replacement lead time are as important as the first sample.
What Information Is Needed for a Broaching Quote?
| Information | Details to provide |
| Part files | A controlled 2D drawing and, where available, a 3D model |
| 재료 | Material grade, specification, supply condition, and any certificate requirements |
| 열처리 | Process sequence, final hardness, case depth, distortion limits, and whether hard broaching is required |
| Broached feature | Profile dimensions, tooth or groove data, broached length, starter-hole size, chamfers, and reliefs |
| 공차 | Size, profile, pitch, position, runout, surface finish, and identified critical characteristics |
| 점검 | Applicable standards, gauge requirements, measurement method, report format, and sampling frequency |
| 수량 | Prototype quantity, order quantity, annual demand, program life, and production schedule |
| Commercial requirements | Target delivery, packaging, traceability, special approvals, and whether tooling is customer-owned |
The more complete this information is, the easier it is to recommend the correct process and separate one-time tooling charges from recurring part cost. It also reduces the risk of a quotation changing after the broach or fixture design has started.
결론
Broaching combines high output, repeatable geometry, and good surface quality in a single controlled stroke. Its advantages are strongest when the feature, workpiece material, tooling, machine, fixture, cutting fluid, inspection method, and production quantity are planned as one process. It is not the best solution for every part, but for repeat internal splines, keyways, internal gears, racks, and formed profiles, it can significantly reduce cycle time and unit cost.
If your part contains an internal spline, keyway, internal gear, or another complex formed profile, you are welcome to submit a 2D drawing, 3D model, material grade, hardness, and expected quantity. We 웰도 machining can provide DFM recommendations based on the part geometry, help you evaluate the most suitable machining approach, and prepare a more accurate quotation.
자주 묻는 질문
Can a Blind Hole Be Broached?
A conventional linear internal broach normally needs to pass through the workpiece, so a true blind hole is usually not suitable. Short blind polygonal features may be possible with rotary broaching, while blind keyways or internal forms may require slotting, shaping, EDM, or specialized tooling.
Should Broaching Be Performed Before or After Heat Treatment?
Most conventional HSS broaching is performed before final hardening because the material is easier to cut and tool life is longer. If heat-treatment distortion would prevent the final spline from meeting its functional requirements, a controlled soft-broach allowance followed by carbide hard broaching may be used.
Does Every Part Require a Custom Broach?
No. Standard keyway broaches, bushings, shims, and some rotary broaches cover many common sizes. A custom broach is normally required for a proprietary spline, internal gear, combined profile, special tolerance, long production run, or feature that cannot be produced with a standard tool.
How Can You Tell When a Broach Needs Regrinding?
Typical warning signs include increasing cutting force, burrs, tearing, declining surface finish, dimensional drift, poor chip formation, and visible flank wear or edge chipping. Regrinding should be scheduled before severe wear spreads to the next teeth or causes breakage.
