1970 spindle bolt hardness grade (1 Viewer)

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Can you supply a picture of the head(s) as most bolts can be identified by their heads?
 
Considering that they were cross-drilled for the safety wire, I don’t suspect they had the hardness that was really required for that application.

I run widened stock rims and 33s on my trail 40 and have sheared those bolts in the past. Replaced all with 10.9.
 
Does anyone know if the safety wire bolts are 8.8 or 10.9 or other?
I have some broken ones I need to replace.
Thanks
Neither, JIS standards do not include a class 8.8 or 10.9, They are 4T-11T. You should be able to identify the class if the bolt head is marked. However, since this is a specialty fastener that may not do you any good. If I'm thinking what you're thinking the OEM number is a 90103-08003. The normal bolt code does not seem to apply here, and since it is discontinued I can not seem to find an image to help with ID. If you end up using a bolt with a higher yield strength than the OE, still use the OE torque spec, if you have it, as the pre load calculations apply to the bolted connection using the OE fastener.
 
Thanks for the replies.
The bolts don’t have any markings on the heads.
I will have to buy a safety wire drill jig and do this myself I think.
I will buy 10.9 bolts. From what I’ve read they can be drilled out with a good drill bit and the correct speed.
 
Pictures of bolt for reference.

A652E106-D7A2-485D-B26D-88762372C413.jpeg


image.jpg
 
Why not reach out to an aircraft supplier? You might pay a little more for an aviation spec bolt with a safety wire head but you wont be wasting any time drilling and the plating will be inside the hole.
 
Mainly it’s because the part numbers are a nightmare.
If someone wants to chime in with the part number for a grade 10.9 m8x1.25 30mm (22mm thread/10mm blank shank) hex bolt with a drilled head I’m all ears.
 
Mainly it’s because the part numbers are a nightmare.
If someone wants to chime in with the part number for a grade 10.9 m8x1.25 30mm (22mm thread/10mm blank shank) hex bolt with a drilled head I’m all ears.
As stated, the Toyota part number doesn't work like that. Grade, nominal diameter, and length can usually be determined by the last 5 digits but not in this case. There isn't any q0.9 grade in the JIS system. All you need to to is record the following.
  1. Fastener length - tip of bolt to bottom of hex head
  2. nominal diameter
  3. thread pitch
  4. threaded length
  5. head type ( size and safety wire)
  6. The grade you want
Call a supplier and give them this info.
 
Why is it, that disc brake frt ends don't use safety wire? Are the bolt sizes different, threads, strength?
 
Why is it, that disc brake frt ends don't use safety wire? Are the bolt sizes different, threads, strength?
Because it’s not just chat that has become politically correct. No one wants to admit that they didn’t use safety wire when they overhauled their drum brake front end in this cancel culture. :rolleyes: I am almost ready to leave MUD because of this milqtoast mentality.

F135 engines used castle nuts and cotter pins on the connecting rods. The F145, F155 and 2F ALL have the same connecting rods, with the same size bolts, make more horsepower, and don’t use what was no doubt once touted as a critical ‘safety’ feature.
 
Yep, this subject reminds me of left hand threaded wheel studs.
 
I have several hundred of these. Happy to donate a few to anyone placing an order with me.
 
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Because the bolts don't have any markings on the heads means they are probable grade 5.8 or below. Drilling hardened bolts would require using carbide drill bits instead of standard tool steel bits.

Bolt_head_grade_marking[1].jpg
 

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