Generic torque specs - various bolts
 

Are there generic torque specs for specific size bolts?

i.e.

4mm = ?ftlb
8mm = ?ftlb
10mm = ?ftlb
etc

My car is going back together this week and I was hoping not to look up specific torque specs.

Depends on metal of screw or bolt and the metal it is being screwed into. Jim

In the front or back of most manuals like Bentley or Haynes they will have torque specs

with the effort you are about to put into the thing, why not spend the time to look up the torque values? heck just post your questions here, these people are great at giving up the values pronto.

As a general rule of thumb when no torque value is specified -

M6: 14NM
M8: 25NM
M10: 35 - 50NM

As a general rule, you do not want to exceed 14NM on fasteners that use a crush washer (like valve covers) - except of course, the drain plugs.

Double check specifications in the manual, torque values vary widely depending on the application.

AFJuvat

A quick google search (http://www.google.com/search?q=bolt+torque+values&hl=en&lr=&ie=UTF-8&oe=UTF-8&start=70&sa=N) turned up many web pages.

Here's an interesting one:

http://dodgeram.org/tech/specs/bolts/M_bolts.html

http://dodgeram.org/tech/specs/bolts/SAE_bolts.html

HarryD, thanks.

I guess these are maximum torque values. Some are much higher than the specs I know off the top of my head.

Everytime I ask a Porsche tech about a torque value, they always seem to say: "Well thats a 13 MM so it should get xftlbs of torque"

So this is why I asked the original question about generic values.

speaking of being lazy... if there any general guide to the bolt size or nut size based on what size wrench fits it?

For a torque chart ... go to the following site, then to Tech Info, then Section 10 -- Useful Info, then page 10-1027:

http://www.metricmcc.com/

Usually:
6mm bolts take 10mm wrenches
8mm bolts take 13mm wrenches
10mm bolts take 17mm wrenches
12mm bolts take 19mm wrenches

There are some reduced size nuts on a 911 motor. Some 915 transmissions are bolted to the motor with 10mm nuts that take a 15mm wrench. There's another nut like that that holds the rear engine bracket to the case. Exhaust nuts are another place you may find reduced size nuts i.e. 8mm that take a 12mm wrench.
-Chris

Warren,

Very nice.

Thanks, Chris.