M8x1 left hand tap.

Hi guys!

I'm making new lead screw nuts for my unimat but I'm having problems. Has anyone ordered an M8x1 left hand tap and received one that was actually correct? The eBay ones seem to all be absolute crap, with the pitch being closer to 1.1mm. I currently don't have access to a lathe with metric screw cutting facility so i can't have a go at making my own. Any trusted sources?

Cheers,

Pete

Try Tracy Tools. (01803 325603.

Their catalogue states Left-hand taps & dies available, though more expensive than plain old right-hand. However, their quality and service are good, and they are one of "Our" established suppliers!

I don't have an eBay account but I wouldn't buy anything that way unless it was a private second-hand sale (as the site was originally designed to handle), and then only with care! Judging by many comments I've seen, it seems to have become an outlet for manufacturers of bottom-of-the-range stuff.

Drill Service at Horley would be another suggestion. I got a couple of M10 x 1.0 LH taps and a die from them, some time ago.

cheers

Bill

Rotagrip have them and are usually do decent stuff though they do several brands of taps, they also have an e-bay shop.

I would definitely agree with the suggestions of Drill Service Horley (who I relied upon in my working life) and Tracy Tools, but would also add another. When I repaired my SL tailstock I didn't want to go to the expense of HSS for a one off, so I bought HBM carbon steel taps and die from RDG tools.

They did the job perfectly, and I just re-checked the pitch. (I never thought to do so BEFORE using them as I tend rightly or wrongly to trust anything engraved not just with the size, pitch and direction, but also with the makers name AND the required drill size!

Brian

I haven't rung up anyone yet but had a check on the websites, I found an RH m8x1 on tracy tools. 18 quid for the rotagrip HSS looks good as long as it is genuinely a 1mm pitch, 65% discount sounds a bit suspicious.

I must say the only reason I checked the pitch was because it was about a tenner for a set of 3, of a non standard pitch, and if that wasn't uncommon enough it is left hand!

The idea was to make phosphor bronze sacrificial anti backlash nuts to try and get the backlash and friction down to help with the fitting of CNC, so an investment in a tool likely to last a few sets sounds good.

I just checked back through my emails, and my dodgy tap set did come from rdg tools. They offered me a refund if I sent it back recorded but that would have been half the value of the product.

None of the shops mentioned have one on stock so hopefully ordering they won't just get a bad one from rgd and pass it on!!

Pretty sure the retailer has to pay postage on faulty items as per UK consumer goods act[or similar distance selling regulations]

Tony

You panicked me there Pete, so I cut a thread using the taper tap from my RDG set (bought in April 2017) and set up the plug tap as shown in this photo. 10 turns came to 10.01mm, (+/- perhaps 0.02mm, I don't think my judgement that the wrench was level was more than 5 degrees out). It looks like you got a bad batch, but the worry is, what is in their stock now?

Brian

If going the CNC route go straight to Ball Screws, suitably sized ones for your machine will not break the bank.

I bought the tap September 2018, I lost interest in sending it back but it was bizarre because all 3 taps in the set were wrong according to my pitch gauge.

I would be interested to look into ball screws, but the unimat is absolutely tiny, I don't think anything more than the m8 leadscrew would fit in the cross slide area

Looks like they could actually be 5/16 x 24 (UNF).

Rod

A continental source

MF8 LH

Hopefully Roderick! At least that might actually be useful at some point!

Below is the one I have just received from RotaGrip.

And here is the RGD one!

Good to see my suggestion of Rotagrip worked out, is it a brand name one or just one of their imported ones which I have found fine for threads you are not going to use much, I've a few fine pitch metric ones for them that crop up on gas fittings.

Definately something wrong with that RDG one.

Yes, they ended up special delivering me one out for 4 quid postage which wasn't bad! Only ordered it yesterday!

It was branded TWT UK, never heard of them but looked of decent finish etc.

Edited By Pete Savage on 20/09/2019 14:57:34