What is the cause of fracture of open end blind rivets?

1、 Pulling through: The rivet core of the rivet is pulled out from the rivet body as a whole, and the fracture of the rivet core is not broken, leaving a penetrating hole in the rivet body after riveting. The causes of pulling through phenomenon include: excessive pulling force of the nail core; The diameter of the nail core cap is relatively small; The material of the rivet body is relatively soft; The bore surface in the rivet body is excessively lubricated.

2、 Burr: After riveting, the burr of the broken rivet core penetrates through the rivet body hole; Or the hole in the rivet body protrudes with the tip, forming the burr of the scraping hand. The reasons for burrs are: the diameter of the nail core cap is too small; The material of the rivet body is relatively soft; The drilling diameter of the workpiece is too large; The specification of the rivet gun nozzle is too large; The distance between the nail core fracture and the nail core head is too large, exceeding the actual riveting thickness.

3、 Falling off of rivet head: After pulling rivet, where there is an automatic core pulling rivet machine, the rivet head cannot be wrapped and fall off from the rivet body. The causes of nail head falling off include: excessive diameter of nail core cap; The rivet body is short and does not match the riveting thickness.

4、 Rivet body cracking: After pulling the rivet, the rivet body undergoes a longitudinal crack or is completely cracked. The reasons for cracking of the rivet body include: the hardness of the rivet body after annealing is too high or it has not undergone heat treatment; The diameter of the nail core cap is too large; The content of harmful impurities in the rivet material is too high, or there are interlayer.