Bolt and thread sizes
01-13-2009, 03:38 PM
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Year: 2000
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Bolt and thread sizes
Hey I was wondering what the bolt and thread sizes were for the end links bolts and and the stock tracbar axel mount? I am trying to replace these grade 8.
01-13-2009, 05:17 PM
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The head size of my Track Bar axle bolt is 15mm. Not sure of the threads. The best thing to do is bring one of each into the hardware store or parts store and just tell the counter guy you want so many of each in grade 8. That puts right or wrong on the store and if they end up being wrong take them back for free exchange.
01-15-2009, 02:05 AM
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If it takes a 15m/m wrench, then it should be an M10-1.5 thread. Match the underhead length.
A couple of points on machine screws and bolts:
1) They're not sized by the wrench they take, but the nominal maximum diameter of the threads. While there are 'standard' wrench sizes for various threads, this doesn't always hold. Axle u-joint screws are 1/4"-20 on earlier models, but don't take the 7/16" wrench that is "standard" for 1/4" SAE screws - it's a reduced head, and takes a 5/16" wrench.
2) SAE and ISO are two different animals entirely. Fortunately, you can tell the "standard" screws apart rather quickly - SAE screws are graded for strength on a system numbering 2-9, and this is indicated by a progressive number of hash marks. YES, there is an SAE "Grade 9" - it's rare, but it's out there. Count the hash marks on the screw head, add two, and that's the SAE grade.
ISO screws have a "property class" - it's typically represented by a numeric code, rather than hashmarks. Typical ISO property classes are 8.8 (~SAE5,) 10.9 (~SAE8,) and ~12.9 (~SAE9.) If you see a number stamped in the head that looks like one of those, know immediately that it's a metric/ISO screw.
Know also that there is no such animal as an "SAE 8" screw with a metric thread. SAE is a standard for inch sizes. ISO is a standard for metric sizes.
When replacing screws - particularly in suspension! - replace with the same strength grade/property class as you are removing. There's usually a reason for that sort of thing. As steel gets stronger it gets more brittle, and the failure mode becomes more, er, "dramatic" (instead of deforming and a gradual failure, it tends more toward shattering.) So, if you're pulling out an SAE5 screw, put an SAE5 back in. If you're pulling out a 10.9 screw, put a 10.9 back in.
(I have got to get that "Guide to Fastener Use" written one of these days...)
A couple of points on machine screws and bolts:
1) They're not sized by the wrench they take, but the nominal maximum diameter of the threads. While there are 'standard' wrench sizes for various threads, this doesn't always hold. Axle u-joint screws are 1/4"-20 on earlier models, but don't take the 7/16" wrench that is "standard" for 1/4" SAE screws - it's a reduced head, and takes a 5/16" wrench.
2) SAE and ISO are two different animals entirely. Fortunately, you can tell the "standard" screws apart rather quickly - SAE screws are graded for strength on a system numbering 2-9, and this is indicated by a progressive number of hash marks. YES, there is an SAE "Grade 9" - it's rare, but it's out there. Count the hash marks on the screw head, add two, and that's the SAE grade.
ISO screws have a "property class" - it's typically represented by a numeric code, rather than hashmarks. Typical ISO property classes are 8.8 (~SAE5,) 10.9 (~SAE8,) and ~12.9 (~SAE9.) If you see a number stamped in the head that looks like one of those, know immediately that it's a metric/ISO screw.
Know also that there is no such animal as an "SAE 8" screw with a metric thread. SAE is a standard for inch sizes. ISO is a standard for metric sizes.
When replacing screws - particularly in suspension! - replace with the same strength grade/property class as you are removing. There's usually a reason for that sort of thing. As steel gets stronger it gets more brittle, and the failure mode becomes more, er, "dramatic" (instead of deforming and a gradual failure, it tends more toward shattering.) So, if you're pulling out an SAE5 screw, put an SAE5 back in. If you're pulling out a 10.9 screw, put a 10.9 back in.
(I have got to get that "Guide to Fastener Use" written one of these days...)
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