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Looking for 8-32 flat-head with hex... not phillips

high plains drifter

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Austin Texas
Need something stainless or black oxide at the least. Need to find 3/8" and 1/2". Only finding ones online that look too oversized/ industrial... large head OD ( .359- .317. I need the head smaller dia than that if possible and maybe more lo-profile regarding the angle and/ or bulk of the head. I'm afraid most of what I'm finding online will stick up past flush. The ones I have now are phillips head ( old Associated hdwre) and they're aluminum which isn't ideal for this application but they at least fit well/ flush. Don't want phillips though if I can find hex. If it matters this is for an old project rc10gt chassis.

Am I just spinning my wheels here or is there someone out there making hardwre like this... hobby specific maybe?
 
That's a tough one. Bolts are made to industry standards so unless you find someone that made specialty hardware you might be out of luck.

I use bolt depot for hardware I can't find locally.

You might be able to sand/file/grind the head height down which will make the OD smaller as well. If it's low torque the reduction in hex depth/tool engagement may not matter.

My only other thought is are you positive it's not an m4 bolt? They're real close. 32tpi equals .79mm pitch and the .164" diameter of the threads is 4.16mm. Nevermind. M4 have .7 pitch, not .8. it's late.


Got a local machine shop? They could make you some customs but I imagine the cost would be ridiculous.

These guys say they do as little as 25 pieces custom.
 
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I appreciate the quick reply and the links. I'm not sure if Bolt Depot is one that I saw so I'll dbl check them.

The ones I found also listed standard/ course thread and tbh I'm not sure if that's what I need... looks more fine than pics I've seen but might be the same. And they'll need to go into some aluminum parts on the topside of the chassis so thread has to match.

I don't think I have anyone close by to machine these and like you said... $$$. I have already entertained the idea of doing some light grinding on the underside of the heads and considered that would reduce the OD as well... so I'm already in that mindset a bit. Only thing I hate is that I need 12 of em and with a Dremel, quality control for the whole batch is gonna be tough lol.
 
If you don't have thread pitch gauges you can always take them to the hardware store and check them on nuts or the things they have for that. I'm an old mechanical engineer and have a collection of thread gauges both metric and sae (not old enough for whitworth, nor do I have an MGA)

I've recently found a lot of hardware on Amazon and use my parents' prime account to get free shipping. The shipping kills getting stuff from places like McMaster-carr unless you order enough. Bolt Depot was better.

Only got one pack of crappy m2.5 shcs from Amazon that all had a burr on the 1st thread which cause then to strip out the aluminum wheel hubs. The other stuff has been fine.

Also just found out you can return anything to Amazon and just drop it off at a whole foods. Got one of those less then a mile from home.

Not that I really like Amazon. They sure do make it easy though. Bleh.
 
You could also make the countersink deeper to get standard sized heads to fit flush, but I doubt you want to modify vintage parts.

How old is the chassis?

So just realized that an 8-36 (fine thread and likely hard to find) is damn close to m4x.7 (standard m4 bolt).

Sae hardware drives me nuts. Bicycles are 99.9% metric but still a few hold overs like bottom bracket threading and BMX axles.
 
Have you looked at m4 hardware? Some of the fitment issues you may find has to do with the angle of the head and the chamfer abgle of the chassis US/metric 20240922_230435.jpg20240922_230458.jpg
Left is some hex hardware ofoff ebay or McMaster, i don't remember, and wiuld be the closest. The middle and right are both ofoff aliexpress and torx. None of them are flush on a rc10 chassis. Didn't AE make titanium hardware for a while too? ,1727072079317146593606379277079.jpg
AE aluminum hardware on the right., next to the "closest" i could find to fit my build hardware
 
@Gula- Those pics illustrate exactly my concerns. I don't remember if AE ever made titanium. Everything I have from them is aluminum as far as I know and phillips head.... it's sort of a yellow color. Somewhere along the way I picked up some black ( black anodized maybe) 8-32 but it's phillips as well and this would've been maybe as far back as 20+ years ago. I never considered the similar m4 although AE has their hardware in my old manuals and catalogs listed as 8-32.

@89Industries- I don't have a pitch gauge but I can always run to my local HD to check. I don't mind trying to get an asst of hardware from Amazon... Like you say, returns are easy enough and I do have a UPS drop off here so not too much hassle in that regard. May in fact wind up going that route at this point.

I've considered deepening the countersunk holes in the chassis as that would likely come out cleaner and more consistent than modifying the actual hardware but yeah, I hadn't really wanted to modify this old chassis unless it ultimately comes down to that. This isn't the original tub chassis but rather the updated aluminum plate version that came out sometime in the mid 90's. And I do have two of them but still I'd rather see if I can find some hardware that would work before drilling into either of these chassis plates.

Really appreciate the insight, guys.
 
Wow! Yeah those are prices that'll have me sleeping outside for a few nights. Too rich for my blood.

But I think that Jato might've helped me out here. Just ordered from KNK about $60 worth of hardware. I'll have to see what things look like when received but they had some options that just may work. Thanks, Jato.
 
Wow! Yeah those are prices that'll have me sleeping outside for a few nights. Too rich for my blood.

But I think that Jato might've helped me out here. Just ordered from KNK about $60 worth of hardware. I'll have to see what things look like when received but they had some options that just may work. Thanks, Jato.
Awesome. Glad I could help! You're welcome.
 
Never in my life did I ever find a screw that would fit flush on the bottom for a replacement.
I figured that finding a replacement for these original phillips head 8-32s would be difficult but I had no idea it would be this hard. Anyway... I've got some 8-32's on the way... some are the original phillips/ aluminum which I'm not thrilled if I have to use but I can if I have to. Then I've got some hex-head 8-32's coming that I will see if I can make work one way or another.

Yep, hnoroian... I've run into this issue with flat-head replacements before but in this particular application, they reeeeaaally need to be flush or at least pretty damned close. I did consider enlarging the countersunk holes but there's a couple places that are right up to the edge of the chassis so enlarging those particular holes won't work.

I'll just have to see what I have to work with when all this hardware arrives.
 
So I just thought to look at the spec'd head diameter of a Phillips flat head 8-32 machine screw. It is .285-.312"

That spec for an 8-32 flathead socket screw is .311-.359"

Good luck with the assortment you have coming. I will say a JIS screw driver works better than a Phillips screw driver. They look the same but there are differences. I can explain them if you want, but I doubt you do.
 
So I just thought to look at the spec'd head diameter of a Phillips flat head 8-32 machine screw. It is .285-.312"

That spec for an 8-32 flathead socket screw is .311-.359"

Good luck with the assortment you have coming. I will say a JIS screw driver works better than a Phillips screw driver. They look the same but there are differences. I can explain them if you want, but I doubt you do.
Thanks for the info. I think I'm aware of the difference if you're referring to the hardware that Tamiya uses. I actually only recently became aware of the JIS screw-heads when I was looking at building a TT-02 rally car. Fortunately, if I'm forced to use the phillips head style, it's at least pretty large. Removing the old ones wasn't much of an issue due to the large size ( even the ones that were chewed up pretty good or the ones where the phillips slots were a bit rounded/ worn). I was also worried that I might break one since they're aluminum and over 20 years old but that didn't happen and I've got all of the old ones now removed... whew.
 
Fastenal should have an extensive selection of 8-32 stainless and oxide hardware. If you were closer I'd hand you some! I've got a bunch of the stainless stuff on hand in button head and countersunk that all use a 3/32" allen.
 
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