JFBolts, the world leader, Bolts Manufacturer in India, in heat treatment, offers solutions to the challenges of threaded fasteners. With JFBolts, Kolsterising, part of the Special Process Stainless Steel (S³P) group, has been shown to eliminate the problems mentioned above regarding CoF. Kolsterization is a low-temperature carbon-based diffusion process that increases hardness up to 1200 HV0.05 (~72 HRC).
This hard coat has a balance of layers that allows the surface to remain smooth without the risk of brittleness. Unlike other high-temperature coatings, this cured coating is part of the base material, so there is no risk of cracking, peeling or delamination.
There will be no change in segment length after kolsterization, so there is no need to compromise on the received measurement limit. The heat used in this process by threaded rod Manufacturer in India is only used to heat the threaded bar. Increasing the temperature is necessary; it should not interfere with the process, but it is also low enough not to cause any change.
Finally, unlike the practices mentioned above, there is no risk of contaminated sites with sensitive environments such as acute and medical industries. Below is a recent test with commercially available F593G hex bolts and SS 304 Studs and their results on CoF. The parameters of the different tests and the results can be found.
Based on the untreated S1 - S5 tests, it can be determined where the surface degradation is so severe that a small installation can be carried out before the seal itself breaks and is fully secured. This happens at 108 lb-ft (80% power output). However, thread damage was observed even at 54 lb-ft (50% of output torque), which is the industry-recommended dry installation torque for 1/2 in. - 13 stainless steel 316 Studs.
For use, recommended torque settings for carbon steel and 304 Steel Bolts may be near 75% to 80% of their yield strength. A torque of 108 lb-ft is set as the starting point to complete the S6-S8 fasteners. I have done 100 installations with treated bolts and untreated nuts, and there is no sign of binding or thread damage.
The installation torque continues to increase, increasing the torque/efficiency ratio (S8), but there is still no sign of thread deterioration. One particular thing to mention is that only 316 Grade bolts were used in this test die. If the fasteners are assembled from large connectors, finishing the fasteners alone can be a significant improvement. Another way is to solve the nuts used with threaded bolts of different lengths of the same diameter.