Page 15 - MetalForming Magazine March 2022

Tooling by Design
Retainer Screw
Retainer
Die Shoe
Punch Steel
Stripper Plate
Fig. 3—Use spring retainers with strippers.
as compared to keepers; and b) the round shape is readily machined, which reduces machining costs.
3. If the die design requires spools of more than one length, use different diameters to prevent their improper mounting (Fig. 2).
4. Use spring cans around springs in every pad that bottoms out.
5. Use spring retainers to hold springs in the upper die should a pad be removed for service (Fig. 3).
6. For longer nitrogen-cylinder life, do not use the maximum piston travel listed in the catalog. Instead, use 85 percent of rated travel.
7. Do not pre- load nitrogen cylin- ders with the pad
keepers. Provide extra travel (common- ly 1⁄8 to 1⁄4 in.) on the keepers beyond full piston extension.
8. Make the pad travel slightly more than the die work to prevent material from moving due to pad bounce.
9. In progressive dies, all upper pres- sure pads that push stock lifters down as the die closes must have the same
travel length to maintain level strip and lift as the parts locate in each sta- tion. Otherwise, parts may be pulled out of location.
10. Provide windows in the face of large stripper pads to allow easy removal of ball-lock punches.
11. For material greater than 0.045 in. thick, provide pad balancers, which prevent damage to the die caused by pressure pads tipping during the entrance of a new material coil into the die.
12. When a pressure pad will not balance on the stock in the worksta- tions, provide stock balancers to pre- vent tipping.
13. Do not locate springs over a stock balancer as they will provide no hold-down force to the part being formed.
14. Remember that springs located halfway between a pad balancer and the material only provide one-half of the spring force on the stock material.
MF
OPEN, IMMEDIATE PRESS CAPACITY
1000-Ton Press, Max Shut Height: 40 in.
Bed Size: 60 in. front-to-back; 264 in. right-to-left
Feeder Capacity: 0.100 in. at 25-in. coil width 0.060 in. at 48-in. coil width
Send us your die and we’ll run it within one week!
Stamco Industries, Inc.
26650 Lakeland Boulevard Euclid, OH 44132 Phone: 216/731-9333 Email Brian Sopko @ brian.sopko@stamcoind.com
www.metalformingmagazine.com
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