Test Methods & Specs


Understanding Test Methods and Specifications

New methods for determining the strength and breaking/prevailing force of many of our Anaerobic grades have been adopted worldwide, which has led to confusion in result comparisons between old and new data sheets and competitor information, as published.

 

DIN 54454
This is a useful method to determine the 1st movement and subsequent movement through readings taken at 90' intervals to determine breakloose and prevailing strengths of a second fastener.
The method is to assemble a fastener M10x35mm in zinc and to pre-torque the nut to 5Nm using a spacer bar to provide seating. Breakloose is recorded in the standard at 72 hours and prevailing is measured as you loosen the bolt.
Our competition do not use zinc stating they use mild steel and they test at 24 hours not 72 hours. Other variations in methods include a mixture of DIN54454 for 1" movement (Breakloose) and an ISO 10964 test for Prevailing.
 
Variables occur in competitor data sheets and appear as follows:

Typical Breakloose
DIN 24Nm
Range (14 - 34Nm)
(120 - 300 in lbs)
Typical Prevailing
DIN 24Nm
Range (14 - 34Nm)
(120 - 300 in lbs)
Typical Breakloose
ISO 24Nm
Range (15 - 25Nm)
(130 - 220 in lbs)
Typical Prevailing
ISO 24Nm
Range ( 5 – 10Nm)
(  35 -  88 in lbs)

  
ISO 10964
This is the same method as above, but the bolt is not tensioned.  The nut is allowed to run loose.  The results for performance, such as breakloose and-prevailing tend to he much lower readings as shown in the results table above.
Other loose nut/bolt test methods include the USA MIL specifications where two types of fastener are used to determine strength achievement.
 
                                 MIL A 46163 using 3/8 UNC a coarse thread/wide patch
                                 MIL S 22473E using 3/8 UNF a fine thread/short pitch

                                 Materials ISO 10964 Black Oxide Steel Bolts & M10 Bright Steel Nuts

 

Conversion Chart      N.m /daN.cm / lbf..ln / 1Bft

                                 1 N.m = 10 daN.cm = 8.8516f.1n  = 0.73716ft