3/8" UNF countersunk left hand screw?

Hi folks,

I need a 3/8" UNF countersunk screw for my lawnmower, but with a left hand thread. It needs to be at least 7/8" long, but longer is fine as I can cut it down. The head can be a slot or socket (it doesn't matter). Anyone got one, or know of a source? I'd need it mailing to England, but I can PayPal money over straight away.

Any suggestions would be appreciated.

Chris

What is the screw for? I have never seen a left had thread on a lawn mower.

Roger Shoaf

Well, over here in Leftpondia we use right-hand threads and drive on the right side of the road; in Rightpondia they drive on the left side of the road, so maybe left-hand threads are standard there. ;-)

Cheers! Rich

Does it attach the blade?

jsw

It retains a washer which secures the bearing on the end of the cutting cylinder (in the USA, I think you'd describe it as a "reel mower"). Unfortunately, I didn't know the screw was left handed and made a total mess of it trying to get it loose. I should have known better. But now I need a new one, if someone can help.

Chris

The best source of supply would probably be through the parts distribution channel. Do a google search for "lawn mower parts" and have your make a model ready.

Here in the states there are a bunch of outfits that stock or can get each and every part. I googled "lawn mower parts England" and got a lot of outfits looking to sell spares for mowers, so you should be able to find someplace that has your screw. Even if the mower is old that part is probably sitting on someones shelf.

As an example:

Another option would be to go to your local shop that repairs mowers and other outdoor power equipment and see if they got one in the drawer in back.

If that does not work and this is a US model, post the info about the mower make and model and I will see if I can find one around here.

Roger Shoaf

If it helps, a 3/8" UNF lefthand screw is also a common way for a handheld power saw blade to be attached.

I chuckled when I read your response as you've obviously not seen the posts Chris has done before about this mower. IIRC the mower is over 60 years old and the maker is no longer around AFAIK but I can't remember the maker off the top of my head. I remember it being a good British name but that's not going to help much.

Chris,

What about getting a longer 3/8" countersunk screw with a long enough plain section and thread cutting the left hand thread.

I too have a 1950's powered reel mower, and the fingers that make replacement parts are typing this.

jsw

whit3rd Inscribed thus:

Isn't LH 3/8" UNF the same thread used on hand drill chucks ?

Oh no, that's the Dennis. That's finished and running well, bar a few minor adjustments. I keep meaning to make a video of it running. Sometime I will, but for now, here's a picture:

You're right. I could make one, but I'd need a left-handed die, which is probably more expensive than the screw.

Chris

Gunner, you would love it. I'll make a video in the next few weeks, and if you're in England, come and try it out. It's a behemoth needing to be tamed!

Chris

Ooh, that little gal standing in the middle (long reddish brown hair) really does it for me. The guy in front of her really has the SP thing going. He'd fit in a movie. Did you see the movie SteamBoy? Lots of fun. Highly recommended.

Vild, yust vild!

From there:

-- Make up your mind to act decidedly and take the consequences. No good is ever done in this world by hesitation. -- Thomas H. Huxley