Thread Checking Gauge

[Rex Walters]

The rifle sounds like fun.

When I first started with the hobby, I tried hard to stick to SAE tooling. I eventually caved, though, as I started working on more and more metric stuff.

Seems my biggest need for metric stuff is repair work: like it or not, the rest of the world is almost entirely metric, and much of the stuff I find myself repairing was made offshore. I've no real preference for most work, but SAE tooling and hardware is undeniably easier and cheaper to acquire in the US. I still can't single-point metric threads on the lathe, but I rarely have to do anything too big for taps and dies (and my collection of metric taps and dies is filling out nicely).

It definitely helps to have reliable gauges to distinguish between the two systems!

 

[sign216]

Last week I repaired my Kitchenaid refrigerator, and couldn't understand why my metric sockets were fitting so poorly. I assumed it was made out of metric Asian parts, but it was SAE!

I recently bought an English vise, made by Record in England in the 1990's. It was their last model before Record was bought by Irwin and production moved to overseas. I was making soft jaws, found that the jaw screws weren't metric, but inch standard. Interesting that the Record company was sticking to inches, in their metric country.

 

[Deleted member 69715]

For those of you cutting your own threads, there's more accurate options.
Thread wires. For checking male pitch diameters. All you need for those is an accurate o.d. mic and some rubber bands.
Thread rings for male threads. Go-NoGo. Expensive, but worth it.
Thread plug gauges. Go-NoGo. To check internal threads. Also expensive. McMaster Carr, MSC, Any good tool house.

 

[Jake M]

What do people recommend?

I know you're looking for the "other" type, but for repair type work, and identifying fasteners that need to be replaced, it's hard to beat these-

SAE Thread Pitch Gauge

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www.mactools.com

Metric Thread Pitch Gauge

Measures metric threads .Sixteen brass-plated leaves for “pitch" or distance between threads in millimeters

www.mactools.com

In particular I'm not citing the brand, but the exact style. These are two sided, not three or more, and color coded, and readily available. I have these exact ones, but MAC the tool truck model. Stanely/Irwin (in this case) is the exact same thing, they're available in hardware stores and the internet. These should be your "first" set. They're as small of a profile as you're going to find useful, they get into places and things, and get results. If any pitch gauge will solve a problem, these will solve the problem. Best? Well, no. At least not for "everything". But they work for all but the strangest situations, which are inherently not gonna all need the same solution anyhow.

For the screw in style (that you're actually asking about), the wire bound ones are fine I guess, but I find the wire type to be basically a PITA , flipping and flopping around. My preference is the "board" style, but not in plastic. I have this one, and for loose fasteners, I like that form factor a lot better.

https://www.amazon.com/AUPREX-Identifier-Standard-Aluminum-Board-Red/dp/B0CRZ2MKV6/ref=sr_1_31?crid=1EVD2LQIAZ587&dib=eyJ2IjoiMSJ9.rRvT3lEEzedA2Xowo9helAWx204RWjbtFeian-kMRsuWzYCBM_vX3mCMQrYEHdP1q5Jk6iu0DTi81BIJm5EZfxc44fjyhCpGZ9JmPwS7oerHuJXY239_2XOE40REmL8nT-2dl7adeDP1TQ8b5QzwA02TOAsywyfMo952NGzs-KYpMgRvyz03TDarrrnE_p-Z.G2y6TbXxb85Li-wckOEdZHvrH2O3dlwuwrMNCJYFCNE&dib_tag=se&qid=1714822038&sprefix=thread+pitch+gauge,aps,101&th=1

I recently bought an English vise, made by Record in England in the 1990's. It was their last model before Record was bought by Irwin and production moved to overseas. I was making soft jaws, found that the jaw screws weren't metric, but inch standard. Interesting that the Record company was sticking to inches, in their metric country.

For what it's worth, the USA is a metric country. The first tangible beginnings of that were in the late 1800's.

I had a Record vise similar to that if not the same. I didn't know what I had, and let it go with a workbench, as I had a new fancy swiveling pipe vise for the new bench.... Anyhow, it was probably little older I think, but not "old". The threads were absolutely Whitworth. Whatever it was, 1/4? 5/15?, some old timey flat head/chease head, something or other... Not many places stock that sort of thing, SAE does fine there on the original jaws since those screws don't really take any load. (Well.... Shouldn't take any load... Mine needed new for some reason.....) You won't pick that up with a screw on gauge, but on the fold out pitch gauge you can pick up that sort of thing if you're looking carefully.

If that were a joint that actually needed some "structure" to it, respectable clamp load, vibration resistance, fagtigue resistance, some retaining strength commensurate witht he thread size, that has the potential (depending on the application) to be a big compromise.

 

[projectnut]

Be careful when trying to determine thread pitched on items of that age. Often times manufacturers used proprietary threads, or thread pitches that are considered obsolete today. I would try to find an early edition of Machinery's Handbook to see what thread pitches were common in that era.

Many years ago, I inherited an early 1900's Seneca Falls lathe from my wife's grandfather. It came with a number of accessories, and dozens of taps and dies packaged together. When I looked over the taps & dies, I saw they were odd sizes and thread pitches. Some years later when I needed to do some repairs on the machine, I realized these tools were segregated from the others because they were the proprietary sizes and pitches needed to repair the lathe.

Often times manufacturers of that era used proprietary or odd pitch fasteners in an attempt to capture the replacement parts market.

 

[sign216]

Jake M,
Thanks for informative response. The screw-in style, either board or on a wire, are easier, but the leaves have their own merit, esp. with odd sizes. I think I'll get both. Too bad you let the Record vise go, but it had Whitworth threads?! I'll check mine again. The SAE screws fit, but one has some looseness. It could be that I'm putting an SAE screw in a Whitworth hole, although for Record to still be using Whitworth in 1990's would be .... very English of them.

Projectnut,
I hear you on proprietary screw pitches. I was repairing an S&W revolver from the 1800's, and found they were using proprietary screws. Fortunately I found a guy that was making them, and at $25/each (in 1990's dollars) I was able get the screw I needed. I'm repairing a Hopkins and Allen rifle now, from the later 1800's, and hoping I don't run into that again.

Joe

 

[Rex Walters]

Gotta say I'm surprised that anyone finds a pitch gauge (and presumably calipers?) to be the quickest/easiest way to identify fasteners. Thread wires, thread mics, and go/no-go gauges are all useful tools for cutting threads or possibly for identifying specialty/oddball threads, but aren't (IMO) the best tools for identifying standard bolts (the topic of this thread as I understood it).

Every hardware store I've ever been to has some sort of nut and bolt thread gauge available for customers to use, FWIW. I've never seen them leave a pitch gauge out, much less mics, calipers, thread wires, or go/no-go gauges.

As I said, I prefer the cabled version, and the only one there I WOULDN'T recommend is a plastic screw check'r like below (for reasons the OP discovered):

 

[RickKr]

Be careful when trying to determine thread pitched on items of that age. Often times manufacturers used proprietary threads, or thread pitches that are considered obsolete today. I would try to find an early edition of Machinery's Handbook to see what thread pitches were common in that era.

Many years ago, I inherited an early 1900's Seneca Falls lathe from my wife's grandfather. It came with a number of accessories, and dozens of taps and dies packaged together. When I looked over the taps & dies, I saw they were odd sizes and thread pitches. Some years later when I needed to do some repairs on the machine, I realized these tools were segregated from the others because they were the proprietary sizes and pitches needed to repair the lathe.

Often times manufacturers of that era used proprietary or odd pitch fasteners in an attempt to capture the replacement parts market.

I was going to make this point, in part because it became reality for me recently. I was mounting a vintage Redfield peep sight on a 22LR rifle and needed to move a screw (new hole). It was a #1 size screw but did not fit either of the "standard" #1 threads on the plate type thread checker I have. It DID fit in the #2-56 hole, albeit, too loose. I doubt I could have effectively used the fold-out pitch gauges due to the small size. Took quite a bit of searching, but I did manage to find online a 1-56 tap, but never bought it due to the cost and didn't end up moving the screw.

I have a my grandfather's First Edition copy of Machinery's Handbook, but did not think of looking in it for the thread specs. I'll have to look, just out of curiosity. I also have my father's 11th Edition of MH.

I'd never shot a peep sight before, but am loving it. Actually may be shooting better than with a scope.

 

[tq60]

Assuming back in the day, training task was these...either shop class or trades.

I have a couple samples from estate sales, a brass plate with hand stamped identification of thread, clearance hole, untreated hole and threaded hole all in rows

None are complete and have odd sizes.

If screw threads into threaded hole, use other holes as drill bit size guide.

On the list of things to make, but no suitable material handy, plus ti.e is never there.

Sent from my SM-G781V using Tapatalk

 

[sign216]

I was going to make this point, in part because it became reality for me recently. I was mounting a vintage Redfield peep sight on a 22LR rifle and needed to move a screw (new hole). It was a #1 size screw but did not fit either of the "standard" #1 threads on the plate type thread checker I have. It DID fit in the #2-56 hole, albeit, too loose. I doubt I could have effectively used the fold-out pitch gauges due to the small size. Took quite a bit of searching, but I did manage to find online a 1-56 tap, but never bought it due to the cost and didn't end up moving the screw.

I have a my grandfather's First Edition copy of Machinery's Handbook, but did not think of looking in it for the thread specs. I'll have to look, just out of curiosity. I also have my father's 11th Edition of MH.

I'd never shot a peep sight before, but am loving it. Actually may be shooting better than with a scope.

RickKr,
Funny you say that. I'm looking to add a vintage Redfield peep sight to the rifle too. The older Redfield's were made of steel, so they be a good period-correct match to the vintage rifle.

I'd like to make an auxiliary mount, to hold the Redfield, taking advantage of the two screws by the lever. However if the screws are non-standard, getting longer ones to hold the mount may block my plans.