08-08-2019, 07:17 AM
(This post was last modified: 08-08-2019, 07:20 AM by Bob Culver.)
Hi Tony
I gather the variation referred to the typical range of bolt tensions for the same applied torque. Turn of nut method +- 15%, load indicating washer +- 10%; bolt elongation 3-5% (25th edition p1404)
Engines dismantled often reveal old replacement gudgeon bolts with letter R indicating standard h.t hardware (S is/was superior)
Working on moderns can be misleading. The bolts produced under very controlled conditons are tightend to remarkable torques.
For 45 tsi steel typical recommendation for BSF 1/4 7.5 ilbs.ft, 5/16 15 lbs.ft
It has been covered before but torque wrenches can be calibrated with weights. In the 1960s when expensive my father and self made wrenches from a piece of old axle and a length of 1/2 inch ht steel. See them now at swapmeets for $5!
I gather the variation referred to the typical range of bolt tensions for the same applied torque. Turn of nut method +- 15%, load indicating washer +- 10%; bolt elongation 3-5% (25th edition p1404)
Engines dismantled often reveal old replacement gudgeon bolts with letter R indicating standard h.t hardware (S is/was superior)
Working on moderns can be misleading. The bolts produced under very controlled conditons are tightend to remarkable torques.
For 45 tsi steel typical recommendation for BSF 1/4 7.5 ilbs.ft, 5/16 15 lbs.ft
It has been covered before but torque wrenches can be calibrated with weights. In the 1960s when expensive my father and self made wrenches from a piece of old axle and a length of 1/2 inch ht steel. See them now at swapmeets for $5!