Shear type dies have been produced by Altman Mfg. Co., Inc. since 1945 and have some outstanding characteristics. The most important is the extremely long life of the tool. Our customers report these tools last eight to ten years with some sharpening. It is not uncommon for a die which is 20 to 25 years old to be returned for repair or rebuilding. Therefore, when a tool of this type is ordered, it will last usually for the life of the job. Customers have shipped our dies to other countries because they last and run trouble-free for long periods. The dies are built with wear-resistant tool steel and are hardened to 60 Rockwell. To cut rubber effectively, our dies are produced with less than .0005" inch total clearance. This is the total space between the punch and the hole. Our dies are jig ground to give this minimum space and are ground on fixed centers. The spacing which is determined to best match your part is the final spacing produced. This means you have a tool that matches your rubber pad and one which will run trouble-free for many years. Dies do require lubrication while they are being used. The sheet of rubber is sprayed with a soap and water, silicon and water, or soap-silicon and water solution. This first allows the sheet to move freely and helps the parts to fall into the cavity. Secondly, the lubrication greatly increases the length of time between sharpenings.