November 2021 Volume 3

EQUIPMENT & TECHNOLOGY

Insert Tooling for PartsThat Require a Bender When a forged part is C or U shaped, the preform die requires a bender to shape the part. The bender is located on the left wing of the die block and sticks out above the face of the die (either top or bottom). With this positioning, die refurbishment options that include resinking the die block require the bender to be resunk to its original position from the die face, adding extra time and cost to your process. Using die inserts eliminates the need to resink the bender for several impression restorations. The finisher and blocker are manufactured as inserts while the bender and roller remain on the outer wings of the die block. It’s unnecessary to use a die insert for the bender and roller as the die life is over three times that of a finisher and blocker. The die inserts, which are loaded on a dowel and locked into place in the die block, are easy to swap out which significantly reduces downtime. Benders and rollers are normally resunk at a rate of one If your die is expected to last longer than 30,000 hits, you most likely spend a lot of time repairing or refurbishing the die cavities. The downtime associated with these repairs costs your forging shop unnecessary time and money. Switching to an inserted die approach significantly decreases downtime. Inserts can be made with a material of 38 Rockwell hardness (Rc) to 50 Rc and easily coated for more efficiency. The full die block can be made with a material of 36 Rc to 42 Rc, enabling the use of industry standard tool steels at a more cost-effective price. Using a higher alloyed material for the die inserts helps to increase the die life, thus reducing time spent on changeovers and repairs. Additionally, backup die inserts become less expensive to have on hand, enabling worn dies to be replaced quickly and safely. Processing die inserts requires smaller machines and are easier and safer to handle. The cost for heat treating and coating are also reduced as the prices for each are determined by total weight. Insert Tooling for Shallow Impressions Shallow die impressions of 1.25” or less are great candidates for an inserted die approach. Shallow impression inserts can be made of a harder alloyed material with a Rockwell hardness (Rc) of 46 Rc to 50 Rc to further extend die life. Refurbishment becomes inexpensive, as coating, resinking, and heat treating are all priced based on weight. Switching to or starting with an insert die approach will save your operations time and money. Machining the die block to become a die insert holder gives forgers the freedom to manufacture the full die block in a more cost-effective industry standard tool steel. Additionally, the time it takes to refurbish a worn die block is two times as long as it would to create a new die insert. The machines needed to create die inserts are also smaller with lower burden rates than what would be needed to machine a full die block. to four compared to the finisher and blocker. Insert Tooling for High-Volume Runs

FloodWelding for Deep Impressions When your production run is less than 30,000 pieces, without a bender, and deeper than 1.25” flood welding is a great refurbishment option. Flood welding is a solution to repair and refurbish existing die blocks by scarfing out the impression, filling the space with a welded material, and then resinking the die block. A main advantage of flood welding is that you can use a higher alloyed filler material. Repairing worn forging dies with flood welding has been around since the 1950’s. Advances in technology and in the process have made it a cheaper, quicker and more effective way to extend the life of die blocks. However, the process can still be time consuming in some cases. Therefore, it is recommended to use this approach for medium and low volume runs, meaning you won’t need to do it as often. High volume runs most likely would need a second set for rotation to save process time. Also, it is highly recommended not to flood weld in the same position more than three times. After the third weld and resink, remove a half inch off the die face, scarf the remaining cavities and resink as new. This will keep the original die block from carbon depletion and maintain total block hardness.

This information is fromour whitepaper Tooling Selection for Forging Hammers . Download your free copy at https://geminigroup.net/ tooling-selection-for-forging-hammers/. ■

Terry McInerney Account Manager, Gemini Precision Machining, Inc. Phone: 812-374-2105 Email: tmcinerney@geminigroup.net

David Mills Senior Account Manager, Gemini Group, Inc. Phone: 248-804-4929 Email: dmills@geminigroup.net

FIA MAGAZINE | NOVEMBER 2021 15