Determining Die Clearances  In order to receive optimum performance from a punch and die, it is necessary that the proper clearance be provided in the die in accordance with the material to be punched (pierced).  Hole quality (edge roll, and burr), tool life, and slug pulling are results from die clearance. 

•Excessive clearance, although achieves longer tool life, will leave more burr, and leads to slug pulling problems.

 • Insufficient clearance will leave little to no burr, but lessen tool life, and can cause a secondary break .  

Note: Increasing die clearance when holes are close to edge of sheet will minimize distortion of sheet edge.

           EXCESSIVE        INSUFFICIENT         PROPER

           CLEARANCE        CLEARANCE        CLEARANCE

                 

 

There are many factors that may change the optimum clearance value.

 RIGIDITY OF PRESS, MATERIAL GRADE, SPEED OF STROKE

Back to Technical Ref. Index

             

CE TOOLING Clearance Chart

RETURN TO TECHNICAL INDEX

NEXT PAGE

Tech-Index

Type of Material

% of Material

Min

Best

Max

Aluminum, Soft

5

10

15

Brass, 1/2 Hard

6

11

16

Copper, 1/2 Hard

8

12

16

CRS-Mild Steel/Galvanize

10

15

20

Steel D.50C

12

18

24

Stainless Steel

15

22

30

Matt. Thickness X % = Clearance

MATERIAL

MILD STEEL

CRS/HRS 15%

ALUMINUM (SOFT) 10%

STAINLESS

STEEL 22%

BRASS 11%

1/2 HARD

COPPER 12%

1/2 HARD

STEEL

.50 C 18%

INCH”

MM

Gauge

INCH”

MM

INCH”

MM

INCH”

MM

INCH”

MM

INCH”

MM

INCH”

MM

.010

,25

32

.0015

,03

.0015

,03

.002

,05

.0015

,03

.0015

,03

.002

,05

.015

,38

28

.0025

,06

.0015

,03

.003

,08

.002

,05

.002

,05

.003

,08

.018

,45

26

.003

,08

.002

,05

.004

,09

.002

,05

.0025

,06

.004

,09

.024

,60

24

.004

,10

.003

,06

.005

,13

.003

,08

.003

,03

.003

,03

.030

,76

22

.005

,11

.003

,08

.007

,17

.0035

,09

.004

,10

.006

,14

.036

,91

20

.006

,14

.004

,10

.008

,20

.004

,10

.005

,11

.007

,17

.048

1,2

18

.007

,18

.005

,13

.010

,27

.006

,14

.006

,15

.009

,22

.054

1,4

17

.008

,20

.006

,14

.012

,30

.006

,15

.007

,17

.010

,25

.062

1,6

16

.009

,23

.006

,15

.014

,35

.007

,18

.008

,20

.011

,30

.067

1,7

15

.010

,25

.007

,18

.015

,37

.008

,19

.008

,20

.012

,30

.075

1,9

14

.011

,28

.008

,19

.017

,42

.008

,22

.009

,23

.014

,35

.090

2,3

13

.014

,34

.009

,23

.020

,50

.010

,25

.011

,30

.015

,40

.105

2,7

12

.016

,40

.011

,27

.023

,60

.012

,30

.015

,38

.029

,56

.120

3,1

11

.018

,46

.012

,30

.026

,70

.013

,33

.016

,40

.024

,62

.135

3,4

10

.020

,51

.014

,34

.030

,75

.015

,38

.018

,46

.027

,70

.150

3,8

9

.023

,57

.015

,38

.033

,85

.017

,42

.020

,50

.025

,60

.164

4,2

8

.025

,60

.017

,42

.036

,90

.018

,46

.021

,55

.032

,80

.179

4,6

7

.027

,68

.018

,46

.039

1,0

.020

,50

.023

,60

.035

,90

.194

5,0

6

.029

,70

.020

,50

.043

1,1

.021

,54

.025

,65

.038

,95

.209

5,3

5

.031

,80

.021

,55

.046

1,2

.023

,58

.027

,70

.040

1,0

.239

6,1

3

.036

,91

.024

,60

.053

1,4

.026

,70

.029

,75

.043

1,1

.250

6,4

1/4

.038

,95

.025

,60

.055

1,4

.028

,70

.030

,76

.045

1,2

.312

8

5/16

.048

1,2

.031

,79

.070

1,8

.035

,89

.038

1,0

.056

1,5

.375

9,5

3/8

.056

1,4

.037

1,0

.082

2,1

.041

1,1

.045

1,2

.068

1,8

.500

12,7

1/2

.075

1,9

.050

1,3

.120

2,8

.055

1,4

.060

1,5

.090

2,3