A common question is what it the torque for the bolt holding the whatever. “My manual doesn’t list one.” Manuals do not typically list torque for standard fasteners. Manuals list torque values for the non-standard things like the head bolts, which are normally torqued to yield, and the bolts for the bearing caps, which are nonstandard bolts. When you torque a bolt, what you are doing is stretching the bolt, and the torque is an indirect way to get to measure that stretch. For really critical fasteners the correct way to measure is directly. That is why race engines use a lot of studs, instead of bolts. They install a dial or digital indicators touching the end of the stud, and turn the nut until they have stretched the bolt to a calculated value. The standard bolts which secure the oil pan, hold the alternator, etc. are torqued based on the grade or hardness of the bolt, and the bolt diameter and pitch. For the metric fasteners on the minitrucks, the hardness of bolt is stamped on the head of the bolt. And, the diameter and pitch can be measured. You will learn to recognize the size and pitch by eye after a while, but until you get there you can buy gauges which you can use to determine the diameter and pitch. You can pick up an inexpensive one for about $20 on eBay, I searched for “metric thread gauge” and found a bunch. The diameter is just that, and pitch is how far the bolt goes into the hole for one turn. A 6-1.00 bolt is 6mm in diameter, and will go into the hole 1-mm for every full rotation. To get the torque spec, you google for: metric bolt torque table, and look at images, and download one. The tables typically have the bolt size, diameter and pitch, on the left in a column, and row across the top with the different bolt strengths. Just look on the table and it will give you the torque. Better tables will give two measurements, one for a dry bolt, and one for a clean bolt with anti seize or lubricant. (Thread locker is a lubricant when you are torquing a fastener.)
