Noob tries to use a Screw Chek’r

[iwoodsman]

I am suffering from serious ignorance of the history of fasteners. I bought a nifty thread-gauge Screw Chek’r card and started going through the buckets of screws in my house going back to the 1950s, and found that almost no screws old or new were matched by the card… they wouldn’t fit anywhere. The card does outright say that it works for bolts, cap and machine screws only, which tells me that I seem to have a huge collection of “other” screws and maybe metric screws. I Googled a while and didn’t find anyone with my exact confusion. I think I just need an experienced human to confirm for me that the ecosystem of screws really is that large and varied. And that the Screw Chek’r is that limited in it’s scope. And… is there a thread gauge that works with more screws, like wood screws and anchor screws?
In the pic, the few bolts that worked in the card are on the left. A sample of the rejects is on the right.

 

[The Cobbler]

you have a bunch of wood screws, that card is for machine screws & bolts etc .

 

[loganb]

you have a bunch of wood screws, that card is for machine screws & bolts etc .

Bingo

 

[mrjaw14]

Is that actually for checking threads? To me it looks like you put a fastener in a hole and see what drill size may be needed

Edit: tried to read the instructions and it seems to be a little of both. Where’d you get that screw checker?

 

[paulsomlo]

I think your screw checker is probably OK - the vast majority, if not all of the screws on the right are either wood screws or sheet metal screws. The important parameters are the # size and length; I use wood and sheet metal screws all the time, but I couldn't tell you what tpi they are, it's not important. And many of those are tapered anyway, your screw checker is no good there.

All those on the right don't get sorted here, I just throw them in a bucket. If I want to id the machine screws on the left, I use a caliper and a thread gage (leaf type).

 

[msharley]

Is that actually for checking threads? To me it looks like you put a fastener in a hole and see what drill size may be needed

Edit: tried to read the instructions and it seems to be a little of both. Where’d you get that screw checker?

Yep.

It checks threads.

There are different drill requirements for the various tap/thread pitches of a given diameter.

 

[RTM]

Yup, wood screws and at least one sheet metal screw in that right hand mix.

Your screw checker is really built for modern screws, where every screw of a known diameter has the same pitch (threads per inch) or maybe 3 for coarse, regular, and fine.

As I am frequently screwing around with vintage tools, going back to the late 1880s at times, so a modern tool is pretty useless. I have both metric and SAE thread pitch gauges, a digital caliper, and a couple of better screw checkers that tell you the diameter of the screw and the pitch separately. And then for more modern and simple stuff I have a series of standard fine and metric, from number ONE in SAE to quarter inch, and similar in metric.

(Leaf type) pitch gauge


Diameter and pitch for easy stuff, SAE and Metric (better screw checker)


Easy sizes pitch and thread checker, regular and fine I think, (sizes printed on the face)


And for wood screws, this chart from some woodworking magazine works.

 

[RTM]

Is that actually for checking threads? To me it looks like you put a fastener in a hole and see what drill size may be needed

Edit: tried to read the instructions and it seems to be a little of both. Where’d you get that screw checker?

Can you actually see threads in that. I've seen a few with 1-2 threads, others are just thru holes.

 

[geneg]

Just use one of these

 

[geneg]

or these

 

[geneg]

or this

 

[Old tool guy]

Easy sizes pitch and thread checker, regular and fine I think, (sizes printed on the face)

Got a link or a brand name for these?

 

[geneg]

or these:
I also have quite a few of the popular mechanics paper screw charts hanging around.

Wood & tapered screws are by shank diameter & length.

Machine screws (stove bolts) & bolts are by diameter & tpi or metric sizing

 

[iwoodsman]

Exactly the perspective I needed, thanks everyone, also for the good suggestions on decoding wood screws. For those who asked, the Screw Chek’r from Ruelle Industrial was, so I read, the first with that screw-in card that reveals diameter plus thread gauge. The patent expired in the early 70s, Amazon has them plus several similar things available.

 

[The Bean]

I've got one.
Two rows are threaded, one just for diameter.

 

[RTM]

Got a link or a brand name for these?

https://www.amazon.com/gp/product/B01GBZ1K4C/?tag=atomicindus08-20

Currently unavailable

 

[cherrybomb]

Your screw checker actually has two for SAE and two for metric,good quality.Just sort your wood screws by diameter and length,I don't recommend slotted ones unless your matching up a refurbish on a old piece of furniture

 

[Beerhippie]

I like this style:



Metric/SAE, fine and coarse. I sorted probably 50 lb of stainless fasteners with it last winter. I still have another 50 to go.

I just wish there was an easy way to remove them from the cable when checking a thread size on a machine, but be able to replace them on the cable. I may end up ditching the cable and making a rack for them.

 

[Old tool guy]

I have that set. Convenient that they stay in order and all in one place, but sometimes awkward to use.

 

[HoosierMark]

Beerhippie I have those sets also. My Do it Best store has a set mounted on a board. one set has the. Threads for bolts and one set for nuts.

 

[Beerhippie]

Beerhippie I have those sets also. My Do it Best store has a set mounted on a board. one set has the. Threads for bolts and one set for nuts.

Fine if you can bring the part to the board. Not so fine if you need to determine a thread size on a piece of fixed equipment.

 

[Wamsutta]

you have a bunch of wood screws, that card is for machine screws & bolts etc .

I think the 1st hole to the far left on each row is unthreaded.

 

[zendriver]

I was going to go for one of these, but just scrapped the buckets of screws I hae no time to go through.

https://www.amazon.com/JoblikeBrez-Thread-Checker-Wall-Mountable-Identifier/dp/B0CSKSV2PP/?tag=atomicindus08-20

 

[Beerhippie]

I was going to go for one of these, but just scrapped the buckets of screws I hae no time to go through.

https://www.amazon.com/JoblikeBrez-Thread-Checker-Wall-Mountable-Identifier/dp/B0CSKSV2PP/?tag=atomicindus08-20

I figure I saved far more time on hardware store runs than I spent sorting the fasteners. Of course, all I've sorted so far were the smaller--7/16" and down--stainless fasteners. The steel ones may wait for a while....

But having a nicely organized bin of the most common sizes right at hand is... handy.

 

[mikey03]

Whatever you do don’t do what I did at one point which is to try different thread restore taps until one lined up. After I tried all three m10 x 1 and 1.25 and 1.5 and none fit too good I knew I made an error in judgement. Then I bought a pair of thread gauges one metric one sae I actually went snap on because they were made in US and only like 10 bucks each new.

then I made a spreadsheet on my phone that breaks down fraction inch to decimals so I could use a digital caliper to find sae sizes diameter

i also tried using my caliper to measure threads but it’s hard so that’s why I got those gauges. Because for metric you got to measure the distance between the threads and honestly kind of hard to hold the caliper 0.25mm apart and tell the difference.

and for sae you got to count the number of threads that occur over a certain distance I think maybe 1 inch? and it was easy to move the caliper to 1 inch or whatever it is but then to count the threads and keep track is hard even with young eyes

 

[NoahG]

Yup, wood screws and at least one sheet metal screw in that right hand mix.

Your screw checker is really built for modern screws, where every screw of a known diameter has the same pitch (threads per inch) or maybe 3 for coarse, regular, and fine.

As I am frequently screwing around with vintage tools, going back to the late 1880s at times, so a modern tool is pretty useless. I have both metric and SAE thread pitch gauges, a digital caliper, and a couple of better screw checkers that tell you the diameter of the screw and the pitch separately. And then for more modern and simple stuff I have a series of standard fine and metric, from number ONE in SAE to quarter inch, and similar in metric.

(Leaf type) pitch gauge


Diameter and pitch for easy stuff, SAE and Metric (better screw checker)


Easy sizes pitch and thread checker, regular and fine I think, (sizes printed on the face)


And for wood screws, this chart from some woodworking magazine works.

I need those plastic gauges. Any chance you could scan that chart? I like the old ones better than modern designs.

I like this style:



Metric/SAE, fine and coarse. I sorted probably 50 lb of stainless fasteners with it last winter. I still have another 50 to go.

I just wish there was an easy way to remove them from the cable when checking a thread size on a machine, but be able to replace them on the cable. I may end up ditching the cable and making a rack for them.

I bought these for the shop I now manage 5 years ago when I first hired on. They’re still blowing minds when I show them to new hires.

 

[RTM]

Any chance you could scan that chart? I like the old ones better than modern designs.

This one? That one is a magazine freebie, might have another copy. If not will take to work n scan, getting the scale right is important.

 

[Bubba Fett]

I have attempted to sort screws before, but never by thread. That requires more patience than I have. I normally sort them as:
Wood Screws/Drywall Screws and Machine Screws, and each is then sorted by head type (Slot, Phillips, Torx, Hex, and then size. However sizes are very general, and I typically go by the recess size instead of thread. For example, Phillips #3 machine screws would be grouped together. I sort security screws and set-screws as well but not by size, since they are less common.

That seems to work pretty well, but a thread checker could be handy for picking out screws.


There are times when fasteners cause a minor existential crisis:

At what point screw not a screw, but a bolt instead? If it is driven directly into another material (wood, sheet metal, etc.) then I consider it a screw, but if it goes through the material, and is secured by a nut, then I consider it a bolt. But a lot of machine screws fit both categories, depending on usage. And what about lag bolts? Those are clearly screws, are they not?

How is my OCD able to cope with this?

 

[Beerhippie]

I need those plastic gauges. Any chance you could scan that chart? I like the old ones better than modern designs.

I bought these for the shop I now manage 5 years ago when I first hired on. They’re still blowing minds when I show them to new hires.

They double as an extremely steam-punk necklace!

My problem with removing the gauges from the cable and making a rack is that I have more storage room for things hanging than sitting flat.

 

[bwringer]

Bolt Depot sells those plastic L-gauges cheeep. Great place to order fasteners, too.

Bolt Depot - L-Gauges

boltdepot.com

They also have other types of thread checking tools:

Bolt Depot - Thread gauges

boltdepot.com

 

[Beerhippie]

I have attempted to sort screws before, but never by thread. That requires more patience than I have. I normally sort them as:
Wood Screws/Drywall Screws and Machine Screws, and each is then sorted by head type (Slot, Phillips, Torx, Hex, and then size. However sizes are very general, and I typically go by the recess size instead of thread. For example, Phillips #3 machine screws would be grouped together. I sort security screws and set-screws as well but not by size, since they are less common.

That seems to work pretty well, but a thread checker could be handy for picking out screws.


There are times when fasteners cause a minor existential crisis:

At what point screw not a screw, but a bolt instead? If it is driven directly into another material (wood, sheet metal, etc.) then I consider it a screw, but if it goes through the material, and is secured by a nut, then I consider it a bolt. But a lot of machine screws fit both categories, depending on usage. And what about lag bolts? Those are clearly screws, are they not?

How is my OCD able to cope with this?

Just to make sure you're confused, there a full-thread and partial-thread screws and bolts. Our Commonwealth brothers call the full-thread ones set- or grub-screws and the partial thread are screw and bolts.

At least, that's how I think it works... them folks talk kinda funny.

 

[mikey03]

Why do you need to know exact wood screw sizes? I always just figured you could eyeball something that would fit. I didn’t think it was as serious as bolts. But I’m no woodworker so please school me on this

you don’t want a wood screw that will punch thru the other side. And prob need some clearance even so it doesn’t deform the other side maybe 3/4 of the depth is max

but also your not sending the coffee table into space so you don’t need to use a 18 inch screw if you can fit an 18 inch screw so using the biggest one that would fit doesn’t seem to be a right gauge honestly

 

[Beerhippie]

Why do you need to know exact wood screw sizes? I always just figured you could eyeball something that would fit. I didn’t think it was as serious as bolts. But I’m no woodworker so please school me on this

you don’t want a wood screw that will punch thru the other side. And prob need some clearance even so it doesn’t deform the other side maybe 3/4 of the depth is max

but also your not sending the coffee table into space so you don’t need to use a 18 inch screw if you can fit an 18 inch screw so using the biggest one that would fit doesn’t seem to be a right gauge honestly

For mounting hardware, you definitely want them to fit the countersink.

 

[RTM]

Why do you need to know exact wood screw sizes? I always just figured you could eyeball something that would fit. I didn’t think it was as serious as bolts. But I’m no woodworker so please school me on this

you don’t want a wood screw that will punch thru the other side. And prob need some clearance even so it doesn’t deform the other side maybe 3/4 of the depth is max

but also your not sending the coffee table into space so you don’t need to use a 18 inch screw if you can fit an 18 inch screw so using the biggest one that would fit doesn’t seem to be a right gauge honestly

When attaching two boards together, usually into a Tee shape, the unthreaded portion of the wood screw is preferred to be as long as the top board is thick, or a bit longer, so you can pull them together. If the threads bite in the top board, you will strip the threads you cut in one of them, and hope it’s the top board.

There used to be screw size calculators, if the vertical leg of the Tee is x/y inches, you want z sized screw, minimum of aa inches long for maximum holding power.

There are more thoughts than that, but that’s the two easy ones that jump to mind.

 

[Beerhippie]

When attaching two boards together, usually into a Tee shape, the unthreaded portion of the wood screw is preferred to be as long as the top board is thick, or a bit longer, so you can pull them together. Is the threads bite in the top board, you will strip the threads you cut in one of them, and hope it’s the top board.

There used to be screw size calculators, if the vertical leg of the Tee is x/y inches, you want z sized screw, minimum of aa inches long for maximum holding power.

There are more thoughts than that, but that’s the two easy ones that jump to mind.

A wood screw with threads too long for the job will usually result in "bridging", where the threads actually prevent the two boards from being drawn tight together. The problem can also be addressed by using a stepped drill bit that leaves a clearance hole in the top board--like most bits made for use with pocket-hole jigs. Then you just have to worry about having the right size stepped bit....

 

[kaymccampbell]

I have that set. Convenient that they stay in order and all in one place, but sometimes awkward to use.

Much less awkward than the card when you're trying to size an empty hole in a machine.