How to select proper cutting clearance between punch & Die.
Determine the Stock Group by tensile strength of the part material. (See Material Chart at bottom if you don’t know tensile).
Select the Jektole Clearance expressed as % of stock thickness [T] for maximum productivity. Clearance values are per side.
If your material is in the high range of tensile, use the higher clearance; if in the low range, use the lower clearance. Ex.: 40,000 P.S.I. 10%; 60,000 P.S.I. 11%
If burnish length is the main criterion, select the clearance that produces burnish needed.
If the burnish length with Jektole Clearance does not meet your needs, choose Regular Clearance.
Reducing the clearance increases the burnish length and wear on the punch.
Hardness values are based on commercial data available from various sources and are considered approximate.
The Rockwell scale readings used include:
C hard steels and materials harder than B100
B soft steels and non-ferrous alloys
F annealed non-ferrous alloys and thin soft metal strips and sheets.
Low “F” values have been interpolated from Brinell readings.
Note: Information is courtesy of Dayton Progress Corporation and is for reference only.
Disclaimer: Information provided is for reference only. Austek Design will not be responsible for any loss or damage caused by the information provided.