This article summarizes 17 common problems of stamping dies and lists some solutions for your reference.

17 Common Problems And Solutions For Stamping Dies

1. Scrap jump hole

1) The length of the punch is not enough, cut into the die according to the edge of the punch, add a thickness of 1mm to replace the punch

2) The gap of the die is too large, cut the insert to reduce the gap or use a drape machine to reduce the gap

3) If the punch or template is not demagnetized, use a demagnetizer to demagnetize the punch or template

2. Blocking holes with waste

1) The blanking hole is small or the blanking hole is offset to enlarge the blanking hole to make the blanking smooth

2) The blanking hole is chamfered, increase the blanking hole to remove the chamfer

3) The taper of the knife-edge is not placed, the line cutting taper or the reverse side expansion hole reduces the length of the straight wall

4) The straight wall of the knife-edge is too long, and the reverse side is drilled to shorten the straight wall of the knife-edge

5) The cutting edge collapsed, resulting in a large drape, blocking the material and re-grinding the cutting edge

3. Poor cover

1) The cutting edge collapsed, causing the drape to be too large and re-grind the cutting edge

2) The gap between the punch and the die is too large, the line is cut into the block, and the gap is reconfigured

3) The poor finish of the knife-edge of the die and the polished knife edge has a straight wall

4) The gap between the punch and the die is too small, save the die again and match the gap

5) If the ejecting force is too large, pull out the front to change the spring to reduce the ejecting force

4. Uneven cut edges

1) Positioning offset adjustment positioning

2) With unilateral molding, pull the material to increase the pressing force and adjust the positioning

3) Design error, resulting in uneven connection of the knife, re-line cutting, and cutting edge inserts

4) Feeding is not allowed to adjust the feeder

5) The calculation of the feeding step is wrong, recalculate the step, and re-fix the tool position

5. Punch is easy to break

1) The closing height is too low, and the cutting edge of the punch is too long to adjust the closing height

2) Improper positioning of the material causes the punch to cut one side, adjust the positioning, or the feeding device breaks due to uneven force

3) A scrap of the lower mold blocks the knife-edge, causing the punch to break and re-drill the large blanking hole to make the blanking smooth

4) The fixed part of the punch (splint) and the guide part is repaired or re-cut into the block to make the punch up and down smoothly (boarding) offset

5) The guide of the punching board is poor, causing the punch unilateral force to re-fit the punching gap

6) The cutting edge of the punch is too short, and it interferes with the punching board and replaces the punch again to increase the length of the cutting edge.

7) The punch is not fixed well, move up and down to fix the punch again so that it cannot move up and down

8) Punch cutting edge is not sharp, re-grind cutting edge

9) The surface of the punch is strained, and the punch is not evenly stressed when the material is removed. Replace the punch again

10) The punch is too thin, too long, and not strong enough to change the punch type

11) The punch hardness is too high, and the punch material is wrong. Replace the punch material and adjust the heat treatment hardness

6. Iron filings

1) Recalculate the bead position or bending position when the bead is misplaced

2) The bending gap is too small, extrude the iron filings to adjust the gap, or grind the forming block, or grind the forming punch

3) The bending punch is too sharp to repair the R angle

4) Too little material for the cutting edge reconnect the cutting edge

5) The bead is too narrow to re-grind the bead

7. Poor sprouting

1) The center of the bottom hole of the sprout and the center of the sprout punch do not coincide. Determine the correct center position, or move the sprout punch position, or move the sprout-side high-side low or even break the pre-punching position, or adjust the positioning

2) The gap between the dies is uneven, resulting in low budding-side high-side trimming and the low budding gap or even breakage

3) The bottom hole of the sprouting does not meet the requirements, resulting in the height of the sprouting and the recalculation of the bottom hole diameter. The pre-punching hole increases or reduces the diameter deviation or even breaks.

8. Poor molding

1) The punch of the forming mold is too sharp, which causes the material to be cracked. The forming punch repairs the R angle, and the R angle is properly repaired at the knife edge.

2) The length of the forming punch is not enough, resulting in failure to form the correct length of the punch and adjust the actual length of the punch to meet the requirements

3) The forming punch is too long, and the material at the forming part is deformed under pressure. Even if the correct length of the punch is determined, adjust the actual length of the punch to meet the requirements until the punch breaks.

4) The material at the forming part is not enough to cause cracking, calculate the unfolded material, or repair the R angle, or reduce the forming height

5) Poor positioning, resulting in poor molding, adjust positioning or feeding device

6) The forming gap is too small, causing cracking or deformation.

9. Bending size

1) The mold is not adjusted in place, resulting in an angular error, which leads to a poorly adjusted closed height or a poor angle difference.

2) Insufficient elasticity causes poor angles and leads to size deviations. Replace springs

3) The material does not meet the requirements and the angle is not good, which leads to the size change or re-adjust the gap deviation

4) Material thickness deviation causes poor angle, which leads to size deviation to determine the material thickness, change the material or readjust the gap difference

5) Improper positioning leads to size deviation, adjust positioning to make the size OK

6) Design or machining errors caused repair welding and grinding between the bending male pieces, eliminating the gap between the pieces, resulting in small bending dimensions

7) The forming male has no R angle, and the bending height is too small under the angle and other normal conditions.

8) The bending size on both sides is too large.

9) Unstable size caused by unilateral bending and pulling of materials, increase spring force, adjust the positioning

10) The gap is unreasonable, causing poor angle and size deviation to repair the gap

11) The height of the folding knife is not enough, and the folding punch is too short to increase the height of the folding knife, so that the folding punch is inserted into the folding knife as much as possible, resulting in more bad angles

12) The speed during bending is too fast, causing deformation of the bending root, adjusting the speed ratio control, and choosing a reasonable speed

13) The structure is unreasonable, the folding knife is not inserted into the fixed template, and the groove is re-milled. When the folding knife is inserted into the template, the gap becomes larger.

14) Insufficient hardness in the heat treatment of the forming male, causing the crimping line to collapse or the re-forming male crimping line to be flattened

10. No discharge

1) Improper positioning or improper feeding adjust positioning or feeding device

2) The avoidance is not enough to repair the avoidance

3) The inner guide pin is strained, resulting in unsmooth boarding activities. Replace the inner guide pin

4) The punch is strained or the surface is not smooth. Replace the punch

5) Unreasonable positioning of the ejector pin, re-orbit the position of the ejector pin

6) The ejecting force is not enough, or the ejecting force is not enough, replace the ejecting spring or ejecting spring

7) The punch and the splint do not cooperate smoothly. Repair the punch and splint to make the punch cooperate smoothly.

8) Forming a sliding block does not fit well, trimming the sliding block and the guide groove to make them fit smoothly

9) The heat treatment of punching is unsuitable. After a period of stamping, it deforms and re-grinds the punch to correct the deformation.

10) The punch is too long or the length of the ejector pin is not enough to increase the length of the ejector pin or use a punch with a proper length

11) Replace the punch when the punch is broken

12) The template is not magnetized, the workpiece is brought up to demagnetize the template

11. Feeding is not smooth

1) The mold is not set up correctly, which causes the material belt to be out of the same straight line with the feeder, and the mold re-frame or adjust the feeder

2) Adjust the leveling machine or replace the material with uneven material

3) Non-unloading results in feeding irregularities. Refer to the solution of non-unloading

4) Positioning is too tight to adjust the positioning

5) The guide pin is too tight or the straight wall is too long to adjust the guide pin

6) The punch is not fixed well or too long and interferes with the material belt. Replace the punch with the right length and fix it again

7) The ejector pin is too short, and the material belt interferes with the formed block. Adjust the length of the ejector pin to avoid interference

8) Improper arrangement of the position of the floating block to adjust the position of the floating block

12. Poor riveting

1) Improper mold closing height, riveting is not in place, adjusting the closing height

2) The workpiece is not put in place, and the positioning deviation is adjusted.

3) Before riveting, if the workpiece is bad, confirm the sprouting hole. Refer to the solution of the sprouting hole to confirm whether the riveting hole is chamfered. If there is no chamfer, increase the chamfer.

4) The length of the riveting punch is not enough to replace the punch with a suitable length

5) The riveting punch does not meet the requirements, confirm and use the riveting punch that meets the requirements

13. Missing or

    installing

1) Carefully make the wrong punch when assembling accidentally

2) Punch has no direction mark. Mark the directional punch

14. Wrong screw installation

1) Don’t know the thickness of the template, understand that the thickness of the template is too long or too short

2) Insufficient care and experience to choose appropriate screws

15. Disassembly and assembly
    

    of molds

1) The pinhole is not cleaned. Wipe the pinhole and the pin clean. When removing the mold, the positioning pin should be removed first. When the mold is easily damaged, use the screw to guide the hole first, and then drill the positioning pinhole.

2) The procedure of assembling and disassembling the mold is not correct. Do not damage the pinhole when knocking down the pin.

16. Locating pin

1) When the whole wall is fuzzed or the mold is too tight due to scratches, carefully check whether the pinhole is fuzzed, otherwise, the pinhole should not be punched out and re-reamed

2) The pinhole is offset or there is no escape hole underneath, add positioning pin escape hole

17. The spring is too long

1) Did not pay attention to the depth of the spring hole, measure the depth of the spring hole, calculate the compression amount of the spring, and re-select the

2) Not careful enough, lack of experience and proper spring bottom dead center