Woodscrew gauges. American vs British

Poignard

Poignard

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I have just cut some #10 cross-grain plugs using a Diston plug cutter [made in the USA] but they are too loose for holes made using a #10 Stanley drill/countersink [made in the UK].

Is this manufacturing tolerance in the cutters or are American woodscrew gauges different from British?
 
AFAIK USA and UK standards for shank/thread size are different, but only slightly so. Head diameters are however less tightly controlled, eg perhaps 1mm variation for either. This may explain your problem. It's maybe better to drill for the plug with a separate drill, but this needs care with a hand held drill.
 
I use a 3/8" plug cutter which I've had for years now and drill the holes using a 3/8" twist drill. I do the same for the ½" plug cutter. Always a snug fit.
 
It's kind of you to offer but I need about 60, in Brazilian mahogany.

I think the long-term answer is to buy matching sets of cutters and countersinks from a decent UK maker, e.g. Trend, and bin the ragbag assortment I have acquired over many years!

I want the plugs to fit their holes tightly so that I can fix them in place with varnish, so that they will be easy to remove later, if needed.
 
Gauge >> UK Dia >> US Dia
2 >>>>> 0.082>>>>> 0.086
3 >>>>> 0.094>>>>> 0.099
4 >>>>> 0.108>>>>> 0.112
5 >>>>> 0.122>>>>> 0.125
6 >>>>> 0.136>>>>> 0.138
7 >>>>> 0.150>>>>> 0.151
8 >>>>> 0.164>>>>> 0.164
9 >>>>> 0.178>>>>> 0.177
10>>>>> 0.192>>>>> 0.19
12>>>>> 0.220>>>>> 0.216
14>>>>> 0.248>>>>> 0.242
16>>>>> 0.276>>>>> 0.268
18>>>>> 0.304>>>>> 0.294
20>>>>> 0.332>>>>> 0.32

So yes there is a MINOR difference in the Gauges however your problem is not the gauge but difference in the plug verses the hole an American #10 screw head is 0.382" dia while "#10" countersink you used is more likely to be 10mm dia or 0.394" or around 12 thou bigger - oops

Suggest you buy a Diston #10 Screw Digger to match your plug cutter.

Or, buy a half decent set of taper plug cutters
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[ QUOTE ]
<snip> from a decent UK maker, e.g. Trend, <snip>.

[/ QUOTE ] /forums/images/graemlins/laugh.gif
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Artificial Intelligence is no match for Natural Stupidity
 
Trend no good, eh?

Probably made in China anyway /forums/images/graemlins/frown.gif

Thanks for the table of sizes.

To add to the fun, we now have metric woodscrews on sale as well. /forums/images/graemlins/confused.gif
 
Screw >Clearance>Pilot hole >>Pilot hole
gauge >Hole >>>in softwood>in hardwood
0 >>>> 1/16 >>> 1/64 >>> 1/32
1 >>>> 5/64 >>> 1/32 >>> 1/32
2 >>>> 3/32 >>> 1/32 >>> 3/64
3 >>>> 7/64 >>> 3/64 >>> 1/16
4 >>>> 7/64 >>> 3/64 >>> 1/16
5 >>>> 1/8 >>>> 1/16 >>> 5/64
6 >>>> 9/64 >>> 1/16 >>> 5/64
7 >>>> 5/32 >>> 1/16 >>> 3/32
8 >>>> 11/64 >>> 5/64 >>> 3/32
9 >>>> 3/16 >>> 5/64 >>> 7/64
10 >>> 3/16 >>>> 3/32 >>> 7/64
11 >>> 13/64 >>> 3/32 >>> 1/8
12 >>> 7/32 >>>> 7/64 >>> 1/8
14 >>> 1/4 >>>>> 7/64 >>> 9/64
16 >>> 17/64>>> 9/64 >>> 5/32
18 >>> 19/64>>> 9/64>>> 3/16
20 >>> 21/64 >>> 11/64 >>> 13/64
24 >>> 3/8 >>>>> 3/16 >>> 7/32

Another one for you Gauge, Shank clearance, pilot in soft wood, pilot in hard wood
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