Engineering Reference
Punch and die clearance is one of the most important parameters in metal stamping. The correct clearance range helps control burr height, cutting force, edge quality, punch wear, tool life, and dimensional accuracy in blanking, piercing, trimming, and progressive die production.
Better cut surface and smaller burr, but higher cutting force and faster punch wear.
Lower punch load and longer tool life, but may increase burr height and edge rollover.
Select clearance based on material type, thickness, hardness, part tolerance, and burr direction.
Punch and die clearance is the controlled gap between the punch cutting edge and the die opening. In metal stamping, this gap allows the sheet metal to deform, shear, and fracture during blanking, piercing, or trimming.
Clearance is usually calculated as a percentage of material thickness. For example, if the material thickness is 1.0 mm and the recommended clearance is 6% per side, the clearance on each side is approximately 0.06 mm.
Single-side clearance = Material thickness × Clearance percentage
| Material | Typical Thickness | Blanking Clearance | Piercing Clearance | Trimming Clearance |
|---|---|---|---|---|
| Mild Steel / SPCC | 0.5–3.0 mm | 4%–7% per side | 6%–9% per side | 3%–6% per side |
| High Strength Steel | 0.8–2.5 mm | 6%–9% per side | 7%–11% per side | 4%–7% per side |
| Stainless Steel | 0.5–2.5 mm | 7%–11% per side | 8%–12% per side | 5%–9% per side |
| Aluminum | 0.5–3.0 mm | 3%–6% per side | 4%–7% per side | 2%–4% per side |
| Copper | 0.3–2.0 mm | 3%–6% per side | 4%–7% per side | 2%–4% per side |
| Brass | 0.3–2.0 mm | 4%–7% per side | 5%–8% per side | 3%–5% per side |
Note: The chart above provides general engineering reference ranges. Final clearance should be confirmed through tooling design review, material testing, die tryout, and production validation.
Example 1
If piercing clearance is 6% per side, single-side clearance is:
1.0 mm × 6% = 0.06 mm
Example 2
If piercing clearance is 10% per side, single-side clearance is:
2.0 mm × 10% = 0.20 mm
Burr height is one of the most visible results of punch and die clearance. If clearance is too large, the material may tear excessively and create large burrs. If clearance is too small, cutting force increases and punch wear or punch breakage may occur.
Heavy burrs, rough fracture surface, poor edge consistency, and possible dimensional variation.
Higher cutting force, faster punch wear, secondary shear marks, and punch breakage risk.
Stable burr height, better edge quality, controlled tool wear, and more consistent production.
Mild steel: usually offers stable blanking and piercing performance with moderate clearance.
High strength steel: often requires larger clearance to reduce cutting load and punch stress.
Stainless steel: requires careful clearance control because work hardening and punch wear can become serious.
Aluminum: may use smaller clearance, but surface protection and galling control are important.
Copper: requires good burr control because many copper stamping parts are used in electrical and EV applications.
In progressive die production, clearance selection affects not only cutting quality but also strip feeding, pilot accuracy, scrap removal, and downstream forming. A clearance problem in one station may cause burrs, chip blockage, punch wear, or feeding instability in later stations.
For high-volume production, clearance should be reviewed together with strip layout, punch strength, material utilization, lubrication, and maintenance planning. Related resource: progressive stamping die troubleshooting guide.
Punch and die clearance should be reviewed when stamping parts show abnormal burrs, poor hole accuracy, rough cutting edges, punch chipping, excessive tool wear, or unstable feeding.
Is the burr direction acceptable for assembly?
Is burr height stable after continuous production?
Is punch wear faster than expected?
Is the clearance value single-sided or double-sided?
Does material hardness match the original design assumption?
Does the part require high edge quality or longer tool life?
Dongguan Changdong Tool & Die Co., Ltd. provides custom metal stamping dies, automotive progressive dies, transfer dies, prototype dies, deep drawing dies, checking fixtures, and sheet metal stamping parts. Our engineering team reviews clearance, material thickness, burr direction, tooling structure, and production volume during stamping die development.
Contact Changdong Tool & Die for stamping die design review, punch and die clearance optimization, burr control, progressive die troubleshooting, and custom metal stamping die manufacturing support.
Changdong is good at making metal stamping dies up to 4.2 meters, also we produce small size metal stamping toolings. The company manages the complete stamping die program from the CAE Simulation, layout designs and stamping tooling designs, and finish the machining to tryout and home line tryout to your hands. Meanwhile, the company produces the prototyping parts and stamping parts range from 45-880T. The successful cases include: stamping tools of Leoni connectors, automotive stamping dies of PSA P8 & B618, metal stamping toolings of Cummins exhaust pipe assembly, automobile stamping dies of NISSAN H60B projects, and stamping tools of car audio system, Canon printers, refrigerators, ovens and washing machines and so on.If you need metal stamping dies ,stamping parts or metal prototypings,
Email to us: sales@chang-dong.com
Engineering Reference
Punch and die clearance is one of the most important parameters in metal stamping. The correct clearance range helps control burr height, cutting force, edge quality, punch wear, tool life, and dimensional accuracy in blanking, piercing, trimming, and progressive die production.
Better cut surface and smaller burr, but higher cutting force and faster punch wear.
Lower punch load and longer tool life, but may increase burr height and edge rollover.
Select clearance based on material type, thickness, hardness, part tolerance, and burr direction.
Punch and die clearance is the controlled gap between the punch cutting edge and the die opening. In metal stamping, this gap allows the sheet metal to deform, shear, and fracture during blanking, piercing, or trimming.
Clearance is usually calculated as a percentage of material thickness. For example, if the material thickness is 1.0 mm and the recommended clearance is 6% per side, the clearance on each side is approximately 0.06 mm.
Single-side clearance = Material thickness × Clearance percentage
| Material | Typical Thickness | Blanking Clearance | Piercing Clearance | Trimming Clearance |
|---|---|---|---|---|
| Mild Steel / SPCC | 0.5–3.0 mm | 4%–7% per side | 6%–9% per side | 3%–6% per side |
| High Strength Steel | 0.8–2.5 mm | 6%–9% per side | 7%–11% per side | 4%–7% per side |
| Stainless Steel | 0.5–2.5 mm | 7%–11% per side | 8%–12% per side | 5%–9% per side |
| Aluminum | 0.5–3.0 mm | 3%–6% per side | 4%–7% per side | 2%–4% per side |
| Copper | 0.3–2.0 mm | 3%–6% per side | 4%–7% per side | 2%–4% per side |
| Brass | 0.3–2.0 mm | 4%–7% per side | 5%–8% per side | 3%–5% per side |
Note: The chart above provides general engineering reference ranges. Final clearance should be confirmed through tooling design review, material testing, die tryout, and production validation.
Example 1
If piercing clearance is 6% per side, single-side clearance is:
1.0 mm × 6% = 0.06 mm
Example 2
If piercing clearance is 10% per side, single-side clearance is:
2.0 mm × 10% = 0.20 mm
Burr height is one of the most visible results of punch and die clearance. If clearance is too large, the material may tear excessively and create large burrs. If clearance is too small, cutting force increases and punch wear or punch breakage may occur.
Heavy burrs, rough fracture surface, poor edge consistency, and possible dimensional variation.
Higher cutting force, faster punch wear, secondary shear marks, and punch breakage risk.
Stable burr height, better edge quality, controlled tool wear, and more consistent production.
Mild steel: usually offers stable blanking and piercing performance with moderate clearance.
High strength steel: often requires larger clearance to reduce cutting load and punch stress.
Stainless steel: requires careful clearance control because work hardening and punch wear can become serious.
Aluminum: may use smaller clearance, but surface protection and galling control are important.
Copper: requires good burr control because many copper stamping parts are used in electrical and EV applications.
In progressive die production, clearance selection affects not only cutting quality but also strip feeding, pilot accuracy, scrap removal, and downstream forming. A clearance problem in one station may cause burrs, chip blockage, punch wear, or feeding instability in later stations.
For high-volume production, clearance should be reviewed together with strip layout, punch strength, material utilization, lubrication, and maintenance planning. Related resource: progressive stamping die troubleshooting guide.
Punch and die clearance should be reviewed when stamping parts show abnormal burrs, poor hole accuracy, rough cutting edges, punch chipping, excessive tool wear, or unstable feeding.
Is the burr direction acceptable for assembly?
Is burr height stable after continuous production?
Is punch wear faster than expected?
Is the clearance value single-sided or double-sided?
Does material hardness match the original design assumption?
Does the part require high edge quality or longer tool life?
Dongguan Changdong Tool & Die Co., Ltd. provides custom metal stamping dies, automotive progressive dies, transfer dies, prototype dies, deep drawing dies, checking fixtures, and sheet metal stamping parts. Our engineering team reviews clearance, material thickness, burr direction, tooling structure, and production volume during stamping die development.
Contact Changdong Tool & Die for stamping die design review, punch and die clearance optimization, burr control, progressive die troubleshooting, and custom metal stamping die manufacturing support.
Dongguan Changdong Stamping Dies CO., LTD. © copyright Add：NO. 56-B, Fuming South Road, Dalang, Dongguan, P.R.C
E-mail: sales@chang-dong.com Tel: 0086-769-8106 1256 Mobile: 0086-189 2949 4380 Sales Manager: Ms. Alice Fax: 0086-769-8106 1926
Dongguan Changdong Tool & Die Co., Ltd. is a custom metal stamping die and stamped parts manufacturer founded in 2012. We support automotive, home appliance, electrical and industrial projects from DFM review and die design to press tryout, sample validation and metal stamping production.
Main capabilities: Stamping Dies | Progressive Die | Transfer Die | Prototype Die | Prototype Tooling | Stamping Parts | Custom Metal Stamping Parts
For new tooling or stamping projects, please send your 2D drawing, 3D model, material grade, sheet thickness, tolerance requirements, annual volume and sample target date through Contact Us.
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