GMT automatic boring head

[ChrisBParticipant @chrisb35596]

Hi, I need a boring head for my mill so I've been looking around for one at a reasonable price. Most I've seen are of Chinese origin and prices vary widely.

Then I came across this boring head made by GMT France. Never heard of it before and don't know if still in production, but couldn't find any literature about it. From the photos it looked well built and having an R8 arbor makes it perfect for my mill.

I would like to know if someone's familiar with this boring head and what are the opinions of it.

Chris

[ChrisBParticipant @chrisb35596]

Advice/info required before purchase

[John ReeseParticipant @johnreese12848]

I suspect you mean Gamet. I have two, 1/2" and 3/4" bar size. Both are extremely well made and work well. Some were sold here in the US under the Enco brand. If you nee instructions I have them.

[ChrisBParticipant @chrisb35596]

Hi John, thanks. It could be Gamet. On the the head there's a plate which says : GMT. Made in France for Gamet product Ltd. Colchester.

It's the one pictured below.

[BazParticipant @baz89810]

Not just a boring head, it looks like it faces as well. Very good make, in terms of quality up with the likes of wolhaupter, if I were you I would buy it quick before somebody else snaps it up. Worlds apart in terms of quality from the offerings of our Chinese friends.

[ChrisBParticipant @chrisb35596]

Thanks for the feedback gents.

Think I got myself a bargain – no one bid on it, and at £70 it's about the same price of a Chinese heads – hope it comes in working order tho!

[John ReeseParticipant @johnreese12848]

It looks just like mine. One branded Gamet, the other branded Enco.

[ChrisBParticipant @chrisb35596]

Long wait over, almost forgot about it till the postman knocked on the door this morning!

Looks mostly complete, maybe missing a set screw for the gibs adjustment.

The strange thing is the boring bar holes – they are 14.00mm in diameter (, what size is that? Closest imperial size is 1/2", and the boring bars it came with are 1/2" but they fit loose (there is an adaptor sleeve) Are 14mm bars common?

Also the boring bars it came with are branded "Boremasters of Kenilworth LTD" "Spacemakers tool no…" must be an old defunct company as I found no hits on google

[Andrew TinsleyParticipant @andrewtinsley63637]

I googled Gamet and found it was an Indian based company. I did this when I saw a bargain chuck bearing the name. So now I am confused, is it an Indian supplier or European company? Or are there two separate companies with the same name?

Andrew.

[ChrisBParticipant @chrisb35596]

Posted by Andrew Tinsley on 21/08/2019 16:29:55:

I googled Gamet and found it was an Indian based company. I did this when I saw a bargain chuck bearing the name. So now I am confused, is it an Indian supplier or European company? Or are there two separate companies with the same name?

Andrew.

Who knows! The tag on the head says made in France for Gamet Colchester, and the manual it comes with says Gamet products LTD Hythe Colchester Essex England (printed at the Blackfriars press Ltd Leicester, England).

So I doubt it's made in India, but it could be that it was taken over more recently.

Still confused about the 14mm boring bars, it's an annoying dimension! Might be another project for building my own…

[Michael GilliganParticipant @michaelgilligan61133]

Posted by ChrisB on 21/08/2019 16:06:03:

[ … ]

The strange thing is the boring bar holes – they are 14.00mm in diameter (, what size is that? Closest imperial size is 1/2" …

.

With the greatest respect to your measuring skills, Chris:

Are you absolutely sure that the holes are 14.00mm diameter ?

The reason I ask is that 14.2875mm is a 'reasonably convenient' 9/16"

MichaelG.

[ChrisBParticipant @chrisb35596]

Posted by Michael Gilligan on 21/08/2019 18:03:35:

Posted by ChrisB on 21/08/2019 16:06:03:

[ … ]

The strange thing is the boring bar holes – they are 14.00mm in diameter (, what size is that? Closest imperial size is 1/2" …

.

With the greatest respect to your measuring skills, Chris:

Are you absolutely sure that the holes are 14.00mm diameter ?

The reason I ask is that 14.2875mm is a 'reasonably convenient' 9/16"

MichaelG.

It's Ok Michael, to be sure I used a vernier – it's 14.00mm.

The box also has a boring bar which takes HSS bits, the shank on this is 14mm (I think it's part of the original tooling) The rest of the boring bars are 1/2"

[BazyleParticipant @bazyle]

But if it is French made would they want an odd imperial boring bar. France, Germany, Spain, Italy, Sweden all had big engineering bases just like us and they had an odd tendency to make things in metric sizes. Did you google 14mm boring bar? Try **LINK**

[ChrisBParticipant @chrisb35596]

Are lathe and mill boring bars interchangeable? I thought the bars for the boring head had to have the cutting edge aligned to the centre line of the head for clearance etc. On the lathe you can adjust the boring bar to centre height but not sure that can be done on a boring head…but I could be mistaken. If that's not the case I can get a lathe boring bar shorten it and turn it to 14mm (if I don't find any)

Going through the manual it came with there are two versions of these boring heads, metric and imperial, the metric one (which I have ) comes with a 14mm tool shank Dia, the imperial is 1/2".

[BazyleParticipant @bazyle]

With a round bar you just rotate it to give the top rake you desire. Try drawing it as an end view.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by ChrisB on 21/08/2019 18:18:34:

It's Ok Michael, to be sure I used a vernier – it's 14.00mm.

The box also has a boring bar which takes HSS bits, the shank on this is 14mm (I think it's part of the original tooling) The rest of the boring bars are 1/2"

.

Looks like the previous owner must have had difficulty getting 14mm

… Perhaps that's why they sold it, and you [now better-informed] got a bargain.

MichaelG.

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