Thread sizes?

[jmc330i]

Whats the difference between an M6X18 and an M6X20 bolt?

Can an M6x18 be used in place of an M6X20?

[Widge]

Do you mean an M6x2.0 bot and M6x1.8 if so it's the pitch of the thread in mm, so the M6x2.0 will have 2mm between the peaks of two threads. If you try to use one in the other it will screw in about 1 thread and then go tight and if you force it it will strip one the other or both threads, so the answer is not you can't I'm afraid.

[buster]

he must mean length as theres no such pitch as those.So ones 20mm long the other 18,only 2mm difference in length thats all.
M6 is generally 1mm pitch.M6x1.Use a 5 mm drill for tapping it.

[jmc330i]

Do you mean an M6x2.0 bot and M6x1.8

M6X18 is how its written on the ETK. Sorry I have no idea on this stuff

[buster]

yeah thats length mate

[Widge]

Yeah it'll be length, so it shouldn't make that much differance, you can always chop 2mm off the longer one.

[jmc330i]

Excellent, cheers guys

Its the shorter ones I need to use in place of the longer ones, so they should go straight in.

Cheers