Sterling silver gauges

[Patstone]

What is 1mm thick sheet in gauge, there is a list to download of the different saw blades to use with different gauges but no indication as to what mm it is. I seem to snap sawblades for a pastime, so I dont do a lot of piercing because of this. Most of my work is 1mm or 1.50 thick sterling and I normally use a 2/0 sawblade. Is this correct, I also have "0" sawblades.

[Paul Kay]

Gauge to mm and inches (decimals and fractions) conversion chart (B&S or Brown and Sharpe Gauge, the usual gauge measurement for precious metal I think)

Click thumbnail to enlarge

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Note: B&S and AWG are 100% equivalent

[Goldsmith]

Pat, nowadays most gauge sizes referred to on online charts are AWG, American Wire Gauge. If this is like the lists you refer to then this chart will give you an idea of conversion. As for saw blade sizes for 1mm. thick I use 4.0 and 3.0 blades mostly, but for 1.5mm. I would use the 2.0 to 0 sizes, it's the amount of teeth on the smaller blades that can make cutting smoother, bigger blades have larger teeth.

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James

[Maree Hart]

Andrew Berry has a chart of jewellers saw blades and dimensions as a free resource:

http://www.atthebench.com/wp-content/uploads/2014/04/resources_jewellers_blades.pdf

He shows 2/0 as being suitable for metal 0.6 - 0.8mm thick. He recommends grade 3 or 4 for 1mm and 5 for 1.5mm though I imagine you could use 4 for both.

I've personally only ever bought 2/0 blades - I'm still on my first pack of Vallorbe. I don't know if they are much better than others but they don't seem to break for me.

[CJ57]

Pat, nowadays most gauge sizes referred to on online charts are AWG, American Wire Gauge. If this is like the lists you refer to then this chart will give you an idea of conversion. As for saw blade sizes for 1mm. thick I use 4.0 and 3.0 blades mostly, but for 1.5mm. I would use the 2.0 to 0 sizes, it's the amount of teeth on the smaller blades that can make cutting smoother, bigger blades have larger teeth.

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James


I'm still trying to work in BMG James which is really confusing with the new guage and really annoying. Cookson used to have a table in its catalogue that gave you the comparisons so that I knew what I was buying in metric but I don't think they do that now

[Goldsmith]

Just for you Caroline, here is a chart I copied out of an old Johnson Matthey catalogue. It shows BMG sizes alongside metric and inch decimals.

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James

[Paul Kay]

Nice one James,

As a Brummy, born in the (now gone) Loveday Street Maternity Hospital, right on the edge of the Gun and Jewellery Quarters, should I be proud that the Birmingham Metal Gauge (BMG) appears to run in completely the opposite direction to the Birmingham Wire Gauge (BWG or Stub's Wire Gauge) and is also completely different from the Birmingham Gauge (BG) which progresses in the same direction as the BWG while remaining slightly different?

[Dennis]

Andrew Berry has a chart of jewellers saw blades and dimensions as a free resource:

http://www.atthebench.com/wp-content/uploads/2014/04/resources_jewellers_blades.pdf

He shows 2/0 as being suitable for metal 0.6 - 0.8mm thick. He recommends grade 3 or 4 for 1mm and 5 for 1.5mm though I imagine you could use 4 for both.

From personal experience and confirmed by James, I think Andrew uses blades which are too coarse for comfort and neatness of cut. However at the foot of his table there is the rule of thumb, which is traditionally quoted in connection with this:

Remember the idea piercing saw blade for the job required is one that has 3
teeth in contact with the metal at all times. Perhaps it should say 'at least' Dennis.

[ps_bond]

One particularly irksome point with B&S is the thickness varies according to metal...

The maxim of 3 teeth in contact should *definitely* be "at least". I've been piercing steel again - 5.3mm thick, 2/0 blades.

[Maree Hart]

From personal experience and confirmed by James, I think Andrew uses blades which are too coarse for comfort and neatness of cut. However at the foot of his table there is the rule of thumb, which is traditionally quoted in connection with this:

Remember the idea piercing saw blade for the job required is one that has 3
teeth in contact with the metal at all times. Perhaps it should say 'at least' Dennis.

Aaah, that would explain then why I've had no problem using a 2/0 on 1mm metal.

[CJ57]

Just for you Caroline, here is a chart I copied out of an old Johnson Matthey catalogue. It shows BMG sizes alongside metric and inch decimals.

9404

James

:) Thank you James, I'll print it off and pin it up in the workshop