Where to find Grade 8 Sex Bolts, Mating Screws?

I am looking for Grade 8 sex bolts in a 1/2" to 5/8" diameter barrel with a grip range of 3" to 3-1/4".

Prefer to find a tapered seat style for a flush mount.

I can find them in 18-8 Stainless, but I would really like to have Grade 8.

Anyone know any sources for such fastener?

You might try your local bolt supplier and ask for A490 specs. Don't settle for A325.

Sex bolts.......am I missing out on something here?

Wait, tapered seat? You mean flat head? I know of no such thing.

Yeah - sex bolts?

Might start with pichunter................

Ah, c'mon, it was probably just a typo. He probably meant 8 sex bots...

Grainger online, then select store to see if in stock. McMaster has almost any kind of fasteners too.

Doc should know....
paging doc,
paging doc

Trying to decipher the OP. Is this what you're looking for:

https://www.portlandbolt.com/products/bolts/countersunk/

I've always heard them called flat socket head bolts.
https://www.google.com/search?client=firefox-b-1-d&q=flat+socket+head+bolts

1/2- 13 x 3" version.

https://www.lawsonproducts.com/laws...ZmMr3e2xNtAFqYm9MsFDdWpdpsBoCIO8QAvD_BwE

Not sure you can find stainless in grade eight, or sex bolts in grade eight for that matter.

https://www.mcmaster.com/sex-bolts/...ng-barrels-and-screws-for-door-hardware/

These are what I can find in stainless steel.

However I would like to get them in just standard grade 8 steel.

https://www.mcmaster.com/sex-bolts/barrel-diameter~5-8/head-type~flat/for-material-thickness~3-1-4-3-1-2/

These what you're after? When it comes to grading bolts not all types are graded in the conventional numeric way. Particularly when you're dealing with socket heads.

https://spaenaur.com/catalog/B200/#zoom=z

Nope - you can't. I don't think you can harden stainless, even though it's already hard. No way stainless is grade 8. When you need grade 8, you need grade 8!

Tell us what you're using them for

But please no pictures. I don't want to see what any one on here does with sex bolts.

17-4 Stainless is available and very comparable strength wise to typical grade 8, and far superior to typical grade 2 stainless fasteners.

Physical Properties:
Melting Point: 2560 - 2625°F (1404 – 1440°C)
Density: 0.282 lbs/in3 / 7.8 g/cm3
Modulus of Elasticity in Tension: 28.5 X 106 psi / 197 GPa
Mechanical Properties:
Condition: Solution Treated (A)
Tensile Strength Minimum (psi): 160,000
Yield Strength Minimum 0.2% offset (psi): 145,000
% Elongation in 2” Typical: 5%
Hardness: Rockwell B85
Condition: Hardened + Aged (TH1050)
Tensile Strength Typical (psi): 200,000
Yield Strength Typical 2% offset (psi): 185,000
% Elongation in 2": 8%
Hardness: Rockwell C35
Condition: Aged (H1075)
Tensile Strength Typical (psi): 175,000
Yield Strength Typical 2% offset (psi): 165,000
% Elongation in 2": 8%
Hardness: Rockwell C37
Condition: Aged (H900)
Tensile Strength Typical (psi): 210,000
Yield Strength Typical 2% offset (psi): 200,000
% Elongation in 2": 7%
Hardness: Rockwell C45




For reference sake, its likely double the cost of typical SS.

And let’s not forget “mating screws”. Apparently there is a language of love that I never learned.

That's just redundant...pick one.

Irrelevant if no one makes sex bolts in 17-4 stainless.

They are being used to attach a steel liftgate system to an aluminum trailer.

I need the flush head sex bolts so they can mount the steel flange to the aluminum tube, and then install sheeting, or trim over to hide the fasteners from view. Its much more aesthetically pleasing than a bunch of bolts sticking through the side of a trailer.

I want to use grade 8 because of their hardness, and shear strength properties. Stainless might work, but its not the same as grade 8.

Have you enough material thickness to prevent pull through after countersinking? What electrolysis prevention measures are you taking?

Yes there is plenty of thickness, and the holes through the tube are slugged so it can't collapse. The aluminum is a custom double hollow with 0.3125" wall, the steel flange is 1/4" plate.

We will use the same electrolysis prevention as is used to attach steel axle subframes to aluminum trailers, or steel tongue, gooseneck, kingpin, and A frame couplers.

This isn't something being built in my backyard.

I was hoping there was a diverse enough occupational background among the members to help source a piece of hardware that I had not ever tried to locate before.

What you are actually looking for are countersink bolts with Allen heads? We get all out stainless from Applied. McMaster-Carr probably has what you need too.

OK, I had to google "sex bolts" to see what they were, and holy cow! This is what I have been looking for high and low, calling up fastener vendors all over the place with no luck. I had never heard of the term before. The thing that is disappointing is that with all of the specialty fastener companies all over the country that were contacted, none had ever seen what I was showing them in the pics.

So, thank you hp383 for posting this question...my fastener quest has likely been solved; quite a variety of potential sources out there.

Parts Wanted - Challenger SE Trim Screws

OMG! 40+ years in the structural steel business, countless AISC, RCSC, TSSI meetings and I've NEVER heard the term before. I really thought it was a typo for hex bolts and was nonplussed when he mentioned countersunk. Never too late to learn something new.

Note, electrolysis concerns are greater between SS & Alum than Alum and steel, contrary ro what most think.

Seems to me the fastener design sought would have a difficult time achieving a typical marked grade 8 rating, or the needed clamping load.

Ouch.

Guess these aren't what you're after, huh?

True, back in my sailor days I at one time used to refurbish satellite communications antenna. Aluminum castings held together with "CRES" bolts, which is what the Navy calls stainless steel, as in corrosion resistant. Every bolt hole in the aluminum was helicoiled and liberal amounts of antisieze was used to help prevent corrosion. It was very easy to tell when antisieze was not used, because you had to fix the resultant broken off bolt.

Be sure to account for the antisieze's different lubricity and it's effect on the torque values.

wasn't that a rock band in the 80's?

Thank you but no, those are socket head cap screws. Sex bolts are a different product.

I do not want a stainless steel fastener. I know that stainless steel and aluminum do not play well together.

I don't know why many replies seem to assume that is what I am looking for.

I am only able to find stainless steel. But want just a normal grade 8 fastener, possibly zinc coated, or black oxide, the finish isn't my main concern.

So all along I thought you meant "hex" bolt but your last reply got me curious so I GOOGLED "sex bolt" . Well Good luck finding those things in grade 8 !!! I doubt they even come in Grade 2 !!! The head would be the weak point.

I have found them in grade 5

So I will keep hunting.

"I can find them in 18-8 Stainless, but I would really like to have Grade 8." quoted from your opening post.

This could be understood that you wanted grade 8 Stainless, and you have now cleared that up.

I am surprised you found Grade 5, Good luck in your quest.

In your original post where you said is part of what confuses people to what you want since it looks like the sex bolt isn't designed to be flush where a flat socket head bolt IS designed to be flush.

Yes, you could make the sex bolt flush, but it doesn't look like it has a tapered seat under the head.

They are available in button head and tapered seat from most sources. The problem is finding a larger diameter, in a grade 8 steel.

It may not be available, and if that is the case I will look into other means of fastening the lift gate side posts to the trailers.

Okay, when I searched sex bolts it showed ones that weren't flat socket head style, more like a button head.

I only see them in stainless in the sizes and type that you're looking for.

https://www.mcmaster.com/sex-bolts/flat-head-binding-barrels-and-screws/

https://www.boltdepot.com/Sex_bolts_Socket_flat_head_Stainless_steel_18-8.aspx

I suppose that you should tell us where you want to order it. Update, I didn't say that they won't be able to make the shipping in some particular state or something; I just asked to know which websites to advise you. There are a huge number of variants for you; I just wanted to find something more affordable and near you. The best option at this point for you is https://www.scrooz.com.au/nuts-and-bolts/ website, selling many different bolts and stuff for construction and reparation. Be sure that you find the right one and pick all the options correctly to avoid mistakes and problems after shipping.

Tractor trailer parts dealers.

Certainly not cheap. But a very useful fastener.

If I really wanted to use Grade 8 type materials, I believe I would source the correct Gr8 Socket Head Flat Head Screws and fab the sleeve to the desire length. Wall thickness of the sleeve could be controlled for the desired strength.

4130 solid bar or thick wall tubing would be a good material. Can't imagine that the price per piece wouldn't be cheaper.

Not to mention MATING SCREWS

FILM AT 11 !! ..............

they have a lot of choices too

https://www.gardner-westcott.com/

Do be aware of any of the LBGT offerings, They've been know to break down prematurely

Here I was under the impression that in a shear type of mount, a grade 5 is better, as a grade 8 is too brittle. Grade 8s are more for clamping pressure than shear. I think most stock suspension bolts are grade 5, are they not?
Just stirring the pot. Were the old guys wrong in using a grade 5 in shear?l

What I was told too, grade 5 for drive studs on axels more elastic, grade 8 has less shear strength, brittle. A guy had one of those tubular front ends with tubular lcas, while turning backing up slowly a 3/4” grade 8 bolt sheared off, car dropped to ground. Seams like a few had done the same so company made a double shear fix

Should've added for protection after washer LMAO

HMM never heard the above But with most uhh _____ coming from ______ a grade 8 could be a grade 2. I've seen some scary stuff from over there