Capscrew Markings and Torque Values Section V - Specifications - Group 18 Page V-46 M11 Capscrew Markings and Torque Values Caution: When replacing capscrews, always use a capscrew of the same measurement and strength as the capscrew being replaced. Using the wrong capscrews can result in engine damage. Metric capscrews and nuts are identified by the grade number stamped on the head of the capscrew or on the surface of the nuts. U.S. Customary capscrews are identified by radial lines stamped on the head of the capscrew. The following examples indicate how capscrews are identified:
Metric - M8-1.25 X 25 M8 1.25 25 Major Distance Length Thread Between in Diameter in Threads in Millimeters Millimeters Millimeters U.S. Customary [5/16 X 18 X 1-1/2] 5/16 18 1-1/2 Major Number Length Thread Threads in Diameter per Inch Inches in Inches NOTES: 1. Always use the torque values listed in the following tables when specific torque values are not available. 2. Do not use the torque values in place of those specified in other sections of this manual. 3. The torque values in the table are based on the use of lubricated threads. 4. When the ft-lb value is less than 10, give consideration to converting the ft-lb value to in-lb to obtain a better torque with an in-lb torque wrench.
Example: 6 ft-lb equals 72 in-lb. Capscrew Markings and Torque Values - Metric Commercial Steel Class 8.8 10.9 12.9 Capscrew Head Markings 8.8 10.9 12.9 Body Size Torque Torque Torque Diam. Cast Iron Aluminum Cast Iron Aluminum Cast Iron Aluminum mm ft-lb ft-lb ft-lb ft-lb ft-lb ft-lb 6 9 5 7 4 12 9 7 4 14 9 7 4 7 14 9 11 7 18 14 11 7 23 18 11 7 8 25 18 18 14 33 25 18 14 40 29 18 14 10 45 33 30 25 60 45 30 25 70 50 30 25 12 80 60 55 40 105 75 55 40 125 95 55 40 14 125 90 90 65 165 122 90 65 195 145 90 65 16 180 130 140 100 240 175 140 100 290 210 140 100 18 230 170 180 135 320 240 180 135 400 290 180 135