Common Hardware Sizes

Hey this is a really random question, but I'm planning on mounting an aftermarket relay on an existing bolt under the hood. Does anyone know what thread pattern Jeeps use for most of the non-engine hardware (like the bolts that hold the hinges on, etc.). I need to get a nut to tighten the sucker down. I'm assuming it's metric?

kjman2009 said:

Hey this is a really random question, but I'm planning on mounting an aftermarket relay on an existing bolt under the hood. Does anyone know what thread pattern Jeeps use for most of the non-engine hardware (like the bolts that hold the hinges on, etc.). I need to get a nut to tighten the sucker down. I'm assuming it's metric?

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If you can get the bolt out, you can take it into lowe's or home depot and they have these boards with threaded holes in them and you can try it in several different holes to see which size and thread pattern it is, they're labeled to match the packages of bolts and stuff.

I know some one is going to make something perverted out of the things I said lol[-X

blue_kjR417 said:

If you can get the bolt out, you can take it into lowe's or home depot and they have these boards with threaded holes in them and you can try it in several different holes to see which size and thread pattern it is, they're labeled to match the packages of bolts and stuff.

I know some one is going to make something perverted out of the things I said lol[-X

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If you can't get the bolt out, measure it in millimeters the best you can and maybe get a couple nuts that are close, 1 will fit. Don't worry about the pitch, if you determine the diameter, it should be ok to just look for the M? part of the description.

Likely sizes:

DIAM X PITCH
M4 x 0.7
M4.5 x 0.75
M5 x 0.8
M6 x 1

I assume your talking about those studs on the firewall right? Those are a good place for hanging a relay, as a matter of fact the factory foglight and lightbar install harness shows the relay getting fastened down on them.

Looking at them i would guess 10mm, and yes they are going to be metric!

size of your hardware, studs, nuts, try it in several different holes... good grief, I thought this was a family-friendly forum!

(lol)

Yep, exactly - I was looking at the studs on the firewall. I found a sweet spot next to another harness that's tucked away and protected.

TonyCRD said:

If you mean the wrench being 10mm (=3/8) you're right.

The studs are 6mm.

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Yes... Forgive me, dumb Standard guy here so i refer to metric bolts as what size wrench i have to dig around for.... lol

kjman2009 said:

Yep, exactly - I was looking at the studs on the firewall. I found a sweet spot next to another harness that's tucked away and protected.

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Perfect place for them, if the factory does then you can to is the way i look at it...

kb0nly said:

Yes... Forgive me, dumb Standard guy here so i refer to metric bolts as what size wrench i have to dig around for.... lol

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Hehe, I guess I'll be the one to tell him that even in SAE ("standard") a 1/4" bolt doesn't use a 1/4" wrench.

Boiler said:

Hehe, I guess I'll be the one to tell him that even in SAE ("standard") a 1/4" bolt doesn't use a 1/4" wrench.

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It takes a 5/16" wrench

tjkj2002 said:

It takes a 7/16" wrench

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Fixed

http://www.boltdepot.com/fastener-information/Bolts/US-Bolt-Head-Size.aspx

Remember, Metric makes fare more sence than the old antiquated English Standard
measurement system!

Boiler said:

Hehe, I guess I'll be the one to tell him that even in SAE ("standard") a 1/4" bolt doesn't use a 1/4" wrench.

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True, 7/16", but thats like hard coded into my brain. I can literally look at a nut and tell you what wrench size, but if it happens to be a similar Metric size i will end grabbing the standard wrench and then letting out that curse "damn metric" and have to grab the next wrench in the box.

Likewise i can usually look at a bolt, for example a 1/4" and know its 1/4" and then instantly my mind processes that i need a 7/16".

5/16" - 1/2"
3/8" - 9/16"

Etc....

I attribute that to many years of wrenching on the farm. Bugs the hell out of me when i'm working with someone that has to grab 2-3 wrenches and try them all to see which one fits.

Boiler said:

Fixed

http://www.boltdepot.com/fastener-information/Bolts/US-Bolt-Head-Size.aspx

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Not always,99% of all 1/4" hardware I run into uses a 5/16" wrench or a 5/32" allen.

Just like M10 bolts or nuts can take a 15mm or 17mm wrench.

Haha anyways.....I found the nut I needed. It was an M8.

tjkj2002 said:

Not always,99% of all 1/4" hardware I run into uses a 5/16" wrench or a 5/32" allen.

Just like M10 bolts or nuts can take a 15mm or 17mm wrench.

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Ah, you're using square heads

Some company sent me one of these in the mail about 20 years ago. It comes in handy. http://www.rockler.com/product.cfm?page=10890

A pitch guage is handy also.http://www.irwin.com/irwin/consumer/jhtml/detail.jhtml?prodId=IrwinProd100450