Cap screws vs, machiner screws; thread size

[micky]

Cap screws (allen head) vs, machine screws; thread size.

If I want to replace a cap screw, must I use a cap screw?

I have one of those DIY screw seletions and it's usually enough but this time, 6-32 x 3/4" screws screw in but loosely like they can probably wiggle out a thread at a time. (Can they?)

OTOH, 8-32 screws go in 2 or 3 turns and then jamb up. If I had just the right length, that might work pretty well too, but are 3 threads enough?

Since neither fit, one too small and one too big, I suspect that cap screws use a different measuring system? Surely it's not metric ??? since it's Black & Decker. But if it is metric, it seems like it's between M3.5 and M4!!!

This is a Black & Decker GrassHog XP**, version 2, model GH1000 or GH2000, and the screws hold on the guard so rocks won't hit me in the shins, as much, and the after market parts companies sell them, at $3/per, with added shipping $12 for two of them, but (on purpose?) don't say what threads they use.

part 24

Black and Decker refers users to

it says you can eaily order parts, but I've found much harder (not that it would be cheaper but maybe they would give the thread size. Aha, found it, "#24 - SCREW Part# 098119-23 Description SCREW Availability Discontinued List Price $0.99 "

So it's discontinued and they still don't tell what size it was. "Qualify for free shipping on orders over $150!"

Or I think I can stand in the aisle at Home Depot and try various screws, if they're not sealed in their wrapper. They sell a lot of cap-screws (assuming I really need a cap-screw) but I can't find a size betwween 6-32 and 8-32! FWIW this is 6-32:

**Vista, 7, 8, and 10 weren't released when this was made?

2) With some devices, engines? other car parts? is it not true that the threaded hole is made of harder material than the bolts and screws will go in it? Is this generally followed? Almost universally? I'm curious for this case and others: Could I just force in the bigger screw as far as it would go with confidence that if I later removed it, the threads in the hole would still be good for use with the proper screw? Or can I ruin the threads in the hole by twisting in an 8-32 machine screw.

I came across this page, with interesting background, while looking for an answer. I don't know how many of you have believed what.

[Anonymous]

According to this website the 098119-23 screw is Metric, an M4 X 16

Good Luck........

FWIW, we have a B&D trimmer also. However this model use sheet metal (!) screws into plastic to try to hold the shield in place. Have to re-do them every season as they eventually tear out.

[hubops]

I checked WalMart Canada for you -

but they don't mention the thread size either.

John T.

[Dean Hoffman]

Do you have another one you can take out of the machine for a sample? Take it to Ace Hardware if so. They have all sorts of odd stuff and sell them a couple at a time.

[Marilyn Manson]

I'm going to guess "metric". I'm also going to guess your issue is fine thread vs coarse thread.

Again, those are guesses.

Here are the tables for Metric Coarse vs. Metric Fine:

[micky]

I thought I only needed one, but when I took out the other and then repleaced it, it was loose too!

Ace is better than HD or Lowes, but the closest one is a lot farther than they are.

I bought a lawnmower from an ad on Craigslist. When I got there she also had this weedwacker. It's bigger than I need, maybe bigger than I'll ever really use. The first time I tried it, it send hard things into my shins, pieces of the picket fence or something. I noticed the guard was warped. I dont' know if that's why but I bought a new one.

It sort of snaps into place, but I don't expect it stay very long without screws.

I didnt' need this thing, but it was a good price I'm sure, and the woman's husband was injured in a traffic accident and could no longer mow the lawn, and I think I thought it was painful for her to be dealing with things he used to do but could not anymore, so I got it, years ago. Hadn't used it until this summer. He could walk and he was getting better, but slowly.

[micky]

That certainly makes sense for the size that goes in 3 turns and gets stuck, but the places I know don't offer the other thread pitch. They don't even say what pitch they are offering. Unless cap screws come with a different pitch and we're supposed to know that.

That might be. This chart has conversion table and one column is Metric Size-PitchISO and IFI Rec.

So for UNC: 8-32, it says UNF:8- 36

and in metric M4x .7 Where .7 appears to be the PitchISO and IFI Rec.

This page

might explain PitchISO and/or IFI Rec, but I can't read it until this beautiful day ends.

Ths page is too tecnical for me to read at all.

Google has even more than wikip. :-(

[micky]

By golly. When two pags including the one B&D sent me to didn't give the size, I figure no one would.

Home Depot has a bag of 2 for 76 cents. CAn't do better than that.... Except they're not stainless!

Maybe this is better, even if they are a pain to find.

[micky]

Maybe so, since that's what \Retired found me.

Do loose screws like that, one size too small mabye, often wiggle out.

According to \Retired's page, it is metric. Why would an American company do that? Aren't most of their screws English?

Do you think they didn't give the size on purpose, to get people to buy from them?

Is it generally true, not just with cars, that the bolt or screw will get stripped well before a hole will?

Would you force in a screw assuming you could replace it later with the right screw?

[Scott Lurndal]

One of these is quite useful:

[micky]

Oh, yeah, but all the more reason they should give the screw specs, especially when it's "no longer available."

[micky]

Wait a second. It's a hole. I can barely see anything in it.

Okay.

That's true, after I go get the other screw.

Fortunately it was easier to wait for \retired to answer me. ;-) Maybe he has more time because he's retired.

That's a good idea, that I should have though of.

[Clare Snyder]

Because the "American Company" doesn't make it in America - and in China, Taiwan, Korea, Vietnam, Cambodia, the Philapines, or wherever, they DO use metric screws. In dact, virtually everywhere BUT in the USA (and even a lot of what is now "built" in America uses "world sourced" parts which are Metric

[Jim Joyce]

No.

[micky]

Good to know. I was reluctant to do that.

I havent' gotten the replacement screws yet, but as I said, it clicks in and I tried it. My gosh, I think I could power a boat with this thing.

7.2 amps.

I think my other one is 3.8 amps and that worked pretty well.

The one I bought my first summer was the smallest one they sold, i think, maybe 1 amp. and it was really too small, but this one is scary.