Hot take: found out torque specs change on plated bolts and I've been guessing for years | Auto Mechanics - Freelance Forum - The Community for Independent Professionals
Hot take: found out torque specs change on plated bolts and I've been guessing for years
I was flipping through a fastener guide at the parts counter in Toledo last week and saw that zinc plated bolts can need up to 20% less torque than plain ones to get the same clamp load. Been wrenching 11 years and nobody ever said that in any class or shop I worked in. I always just hit the book number and moved on, never thought about coating thickness messing with friction. The guy behind the counter said he sees folks snap intake bolts all the time from over torquing plated hardware. Now I'm second guessing every spec sheet I read off the top of my head. How do you all handle this, do you back off the number or just follow whatever the manual says for that exact bolt?