Need socket head screw with known thread length

[matt_isserstedt]

I need several #6-32 socket head screw x 2-1/2" long, with 1" of thread. More thread is great, I could even do fully threaded.

I spent about a half hour on google with zero results, I ordered a box from mcMaster with 3/4" thread, and studying their drawing it lists a range 3/4" to 1-3/16" thread but no guarantees. Fastenal's CAD doesn't even show threads... :rolleyes:

This is for a repair project at work, with the above screw it will be a fast easy fix. Without i'm into reducing the shank back to the minor diameter with no collets.... or buying a die and cutting new thread...none of which sound interesting for say a qty of 200 screws.

Just wondering if there is any way to predict the thread length of a box of screws before you order...??? I would go that route first to the point of specifiying a specific vendor if I knew what I was getting.

Thanks for any assistance!

[Chobyn]

Surely there is a Fastener vendor in your area......call them, talk to someone. Maybe try the local Fastenal distributor. I do not know who might be in your area, but surely there is SOMEONE. Here, I would call Copperstate Nut and Bolt, tell them exactly what I needed, and then go pick it up......

[specfab]

I think you're out of luck trying to make a prediction. I have also had this issue, and with the standards as "loose" as they are, I suspect this is a total guessing game between mfr practices, and may be also a variation at any given manufacturer. It might be dependent on production schedule for a given length of screw, and what might have been running in the machine previously, which could give allowable variation in thread length. All that being said, I suspect a supplier like HoloKrome probably has a pretty standardized setup for given fastener sizes, although I doubt that they would willingly thread 50% more fastener length than required by spec. The spec variations are more probable in the product lines featuring product that "may be made in any of the following countries: Japan, Germany, Belgium, Borneo, the Maldives, India, Poland, Italy, Greece, Pakistan, China, and Ecuador" or words to that effect....

If you have a few good friends at fastener houses, maybe that can be a help. Good luck --

[billmac]

I'm a bit surprised that there are apparently no standards that define the length of the threaded section of US socket head cap screws. That is definitely not the case for ISO socket head cap screws, where there is a standard length for each size (i.e M6 etc). If you want fully threaded you can get this as well. Isn't there an additional set of say ANSI stds that do the same for US screws? I'm not familair with your standards so just guessing here.

[CarbideBob]

No local bolt store with a warehouse full out back?

In a half hour here I'd have run out to Mid-State, said "Grab me a few boxes from the shelf and let me check them".
I would think there would be somebody left down by you.

Pain in the butt that Applied bought out DBB here in town and shut down the local office.
Life was so much easier when you could walk up to the counter and talk to somebody that actually understood bearings, custom ballscrews and such.
On-line ordering sucks, I hate it, you can't get anyone who understands technical details.

Given your location (spitting distance to the big D) I'm wondering why you go online with buying this kind of stuff.
Bob

[Mike Folks]

Bolt Depot - Nuts and Bolts, Screws and Fasteners online seems to have their SHCS listed as full or partial thread.

[Mud]

I'm a bit surprised that there are apparently no standards that define the length of the threaded section of US socket head cap screws. .

There is, but I don't know where to find it. It's been quoted to me by a salesman who knew it by heart - Something like hex head capscrews have threads 2X the diameter plus 1/2" and socket heads are 2XD plus 1" but CRS has kicked in since then. Sockets are definitely longer than hex heads. So most mfgr's screws are the same. I can believe that machine screw sizes are different from 1/4" and up.

Fully threaded bolts are called tap bolts if that helps the search.

[Clive603]

My handy-dandy Holo-Krome socket screw selector slide rule gives 1" as standard thread length for 6-32 and overall under head length increments of 1/4" from 1" to 3 1/2" long for screws under 1" diameter. Reference is to British Standard 1157-1965 although whether that is purely for tapping sizes and thread classes or for other dimensions I don't know. Memory says that that sort of diameter goes out to 4" or so long tho' whether the long thin ones I had in the handy lab box were UN, BA or metric I don't recall, never having needed them.

Slide rule is around 30 years old but that, along with the companion metric and British thread ones are real handy at times.

Clive

[jkilroy]

How about 6x32 studs with nuts and washers?

[traditional-tools]

Bolt Depot - Nuts and Bolts, Screws and Fasteners online seems to have their SHCS listed as full or partial thread.

Funny, these guys had a 9/16-12 set screw I needed recently. Both 1/2-13 and 5/8-11 are both common, but 9/16-12 is not. They do get an outrageous price, about $3-$6 but they do state "4 This item is a semi-standard size and is therefore more expensive.".

The only other place I could find one at was Fastenal.

FWIW, Bolt Depot looked like they had what Matt was looking for, but doesn't state the thread length. Given the pic, it would appear to be about 1" to 1-1/4" of thread length. A quick call could probably verify that.

[billmac]

My handy-dandy Holo-Krome socket screw selector slide rule ...
Slide rule is around 30 years old but that, along with the companion metric and British thread ones are real handy at times.
Clive

Handy they are - I have the Unbrako version that I use a lot and is at least that old. It has just about everything you need to know.

[metlmunchr]

Matt, go to http://www.holo-krome.com/pdf/Consol...ech_Manual.pdf Scroll down to page 10 of the pdf and you'll see table 2 which gives the grip length for each size and length. Grip length for 6-32x2.5 is 1.5" which indicates it has 1" of fully formed threads.

[matt_isserstedt]

Good info, MM, thanks very much to all who replied, will check HoloKrome via some calls Monday to confirm.

[S_W_Bausch]

socket head cap screw specials - Google Search

Button head:

Skt Cap Screw, BTN, 6-32x1 1/2, Pk 10 - Socket Head Cap Screws - Screws - 2WB68 : Grainger Industrial Supply

Stainless steel:
Socket Cap Screws/Hex Socket Screws: #6 - 32 X 1 1/2 Socket Head Cap Screws Stainless Steel 18-8


For reference:

Smith Fastener Company - Socket Head Cap Screw Specifications

[screensnot]

I am friends with someone who is in the fastener business. I will pick his brain for you on Monday.

It's my guess that he would have these in stock in his warehouse in Livonia. I would be willing to measure the thread length for you (sampling a few per box).

[ZAGNUT]

I'm a bit surprised that there are apparently no standards that define the length of the threaded section of US socket head cap screws. That is definitely not the case for ISO socket head cap screws, where there is a standard length for each size (i.e M6 etc). If you want fully threaded you can get this as well. Isn't there an additional set of say ANSI stds that do the same for US screws? I'm not familair with your standards so just guessing here.

but despite this standard you will still find wild variations in thread length between different lots or manufacturers.

[screensnot]

I can get them for $.60 @ 200qty. 3 days lead time.

[matt_isserstedt]

Sorry to go awol here, but did resolve the problem.

- called various "fastener houses" in metro detroit area I found on google. About 75% didn't even carry "socket products". I remember MidState Bolt and Screw, I worked in Flint around 1991-96 time frame.
- checked Holo Krome - their website does not indicate a #6 x 2-1/2" fastener in their current products, so I abandoned them.
- called Lakeside Kerr - they said they had to check (measure) their warehouse stock and would get back with me. They did call back a day later and say the measurement is 1" of thread.
- however, I had already contacted BoltDepot.com via phone and the person there went and measured his stock of parts in the bin. 1" of thread. So I ordered all he had there, he did state if I order more than his bin qty its going to be a (direct) drop ship with no guarantee. They are in-hand and will be used on the project.

More or less I have a pneumatic assembly for clamping a seal on a part for a leak acceptance machine. It has 3 inline pistons acting on the same shaft to generate the appropriate clamping force in a miniature body. The body is built with modular blocks the first 3 have thru holes, the 4th is tapped all the way thru with a 4 bolt pattern, and there is an end cap with the removable urethane seal that gets mashed into compliance with the production part. All parts of the body are aluminum and the original setup was to bolt from each end with separate screws. Time passed and the seal changed by several different people with different opinions of how much torque to apply to the bolts, eventually the threads got stripped from that end and the machine was down. I got involved in the repair, ended up taking 2" fasteners out of our bolt bin and brazing the shank ends together to make 4pc of a double threaded stud. Shop made 8pc of tapped round stock with a screwdriver flat sawed into the end to get it back together. And so it ran for awhile but I foresee the same problem on all the other examples of this part, and there are 40 tester bodies in use.....so...enter the appropriate fastener, the ever-helpful "allen nut" and I have an easy fix, all-steel threads on the end which gets opened regularly to change the urethane seal, and now I can go dig into another problem

Thanks to all who replied!

[S_W_Bausch]

You may want to suggest a preset torque tool.

The no-hub cast-iron sewer pipes require use of such a tool.