Brand Best Built L&R Quantrex Gesswein Sweep Digital GemOro Elma "Easy" Series Elma "P" Series
Capacity 2 qts., 3.5 qts., 6 qts., 10 qts., 22 qts. 2 qts., 3-3/8 qts., 6 qts., 14.5 qts., 26 qts. 3 qts. 2-1/2 qts. 1.5 pt., 2 qts., 3 qts. 1, 2, 3, 4, 6, 10, 14, 20, 30 qts. 3 qts., 6 qts., 14 qts., 20 qts., 30qts.
Frequency 40kHz 43kHz 42kHz 42kHz 40kHz 37kHz 37/80kHz
Workload Medium to Heavy Medium to Heavy Medium to Heavy Light to Medium Medium to Heavy Medium to Heavy Medium to Heavy
Control Analog Analog Analog Digital Analog Analog Analog & Digital
Timer 0-30 min. 0-60 min. 0-30 min. 5 Different Cycles 0-60 min. 0-30 min. 0-30 min.
Timer Bypass No No Yes No No Yes Yes
Heater Yes Yes Yes Yes Yes
(Except 1.5)
Yes Yes
Housing Powder-Coated Steel Vinyl-Clad Steel Vinyl-Coated Steel ABS Plastic Stainless Steel Stainless Steel Stainless Steel
Tank Stainless Steel Stainless Steel Stainless Steel Stainless Steel Stainless Steel Stainless Steel Stainless Steel
Lid Yes Yes Yes Yes Yes Yes Sold Separately
Drain Yes Yes (except 90) Yes No No Yes (except E15H & E30H) Yes
Country of Origin S. Korea USA USA China China Germany Germany
Ultrasonic Models
Ring Racks
Baskets
Small
Econo
Large
Econo
Long
Rack
Small
Deluxe
Large
Deluxe
Small
Mesh
X-Small
Mesh
Medium
Stainless
Medium
Mesh
Large
Mesh
X-Large
Mesh
Universal
Stainless
Digital 2.5qt* 1 no no no no no 1 no no no no 1
Quantrex 2qt 1 no no 1 1 (remove
2 hooks)
no 1 no no no no 1
Quantrex 3.4qt 1 no 1 diagonally 1 1 (remove
2 hooks)
no 1 no 1 no no 2
Quantrex 6qt 2 2 1 diagonally 2 1 2 2 no no 1 no 2
Quantrex 14.4qt no 2 4 3 3 no no 2 2 1 1 4
Sweep 3qt 1 no 1 diagonally 1 1 (remove
2 hooks)
1 1 1 1 no no 1
Elma SX30H 3qt 1 no 1 1 1 (remove
2 hooks)
no no no no no no 1
BestBuilt 2qt 1 no no 1 1 (remove
6 hooks)
no 1 no no no no 1
BestBuilt 3.5qt 1 1 1 1 1 (remove
2 hooks)
no 1 no 1 no no 1
BestBuilt 6qt 2 no 1 diagonally 2 1 2 2 no no no no 1
BestBuilt 10qt no 2 4 3 1 (remove
2 hooks)
no no 2 2 1 1 2
BestBuilt 22qt no no no no 4 no no no no 1 1 6
Elma E15H 2qt 1 no no 1 diagonally 1 (remove
6 hooks)
no 1 no no no no 1
Elma E30H 3qt 1 no 1 diagonally 1 1 (remove
2 hooks)
no 1 no 1 no no 1
Elma E60H 6qt 2 no no 2 1 2 2 no no no no 1
Elma E120H 14qt no 2 2 2 2 no no 2 2 1 1 4
Elma P30H 3qt 1 1 1 1 1 (remove
2 hooks)
no 1 no 1 no no 1
Elma P60H 6qt 2 no no 2 1 2 2 no no no no 1
GemOro 1.5pt* no no no no no no no no no no no no
GemOro 2qt* 1 no no 1 diagonally 1 (remove
6 hooks)
no 1 no no no no 1
GemOro 3qt* no 1 1 1 1 (remove
2 hooks)
1 1 1 1 no no 1
*Comes supplied with its own basket.
B&S
Gauge
Millimeter
(mm)
Inch
(decimal)
Inch
(fraction)
   B&S
Gauge
Millimeter
(mm)
Inch
(decimal)
Inch
(fraction)
1 7.348 0.289    16 1.291 0.051
2 6.543 0.258    1.191 0.047 3/64
6.350 0.250 1/4    17 1.149 0.045
5.953 0.234 15/64    18 1.024 0.040
3 5.827 0.229    19 0.912 0.036
5.556 0.219 7/32    20 0.812 0.032
4 5.189 0.204    0.795 0.031 1/32
5.154 0.203 13/64    21 0.723 0.028
4.762 0.188 3/16    22 0.644 0.025
5 4.621 0.182    23 0.573 0.023
4.366 0.172 11/64    24 0.511 0.020
6 4.115 0.162    25 0.455 0.018
3.969 0.156 5/32    26 0.405 0.016
7 3.664 0.144    0.396 0.015 1/64
3.572 0.141 9/64    27 0.360 0.014
8 3.263 0.128    28 0.321 0.013
3.175 0.125 1/8    29 0.286 0.011
9 2.906 0.114    30 0.255 0.010
2.778 0.109 7/64    31 0.227 0.0089
10 2.588 0.102    32 0.202 0.0080
2.381 0.094 3/32    33 0.180 0.0071
11 2.304 0.091    34 0.160 0.0063
12 2.052 0.081    35 0.142 0.0056
1.984 0.078 5/64    36 0.127 0.0050
13 1.828 0.072    37 0.113 0.0045
14 1.628 0.064    38 0.101 0.0040
1.588 0.063 1/16    39 0.090 0.0035
15 1.449 0.057    40 0.080 0.0031
Saw
Size
Thickness* Depth Teeth
per inch
For B&S
Gauge
Drill
Size
8/0 .0063" .0126" 89 up to 26 80
7/0 .0067" .0130" 84 24-26 80
6/0 .0070" .0140" 76 24 79
5/0 .0080" .0157" 71 22-24 78
4/0 .0086" .0175" 66 22 77
3/0 .0095" .0190" 61 22 76
2/0 .0103" .0204" 56 20-22 75
0 .0110" .0220" 53.5 18-22 73
1 .0120" .0240" 51 18-20 71
2 .0134" .0276" 43 16-18 70
3 .0140" .0290" 40.5 16-18 68
4 .0150" .0307" 38 16-18 67
5 .0158" .0331" 35.5 16 65
6 .0173" .0370" 33 14 58
7 .0189" .0400" 30.5 12 57
8 .0197" .0440" 28 12 55
* Thickness determines "kerf", the width of the slit left after cutting.
1. Scope and Field of Application
This International Standard specifies the method for measuring the size of rings for the purposes of designating ring-sizes to be used in jewelry.

2. Definition
Ring-size: The inner circumference of the ring expressed in millimeters.

3. Measurement
The inner circumference of the ring should be measured using a tapered ring-gauge (ring-stick) with the following characteristics:
a) length of the measurement scale: 160 ± 0.5 mm
b) minimum ring-size: 41
c) maximum ring-size: 76
d) material: metal, or material with equivalent wear resistance.

4. Designation
The size of the ring shall be designated by the number of this International Standard followed by the inner circumference of the ring expressed in millimeters rounded to the nearest millimeter. Example: Designation for a ring with a ring-size of 43mm measured in accordance with this International Standard : Ring-size IS0 8653 - 43
Circumference (mm)
Europe / ISO
Diameter (mm) USA / Canada UK / Australia Asia Switzerland
44.2 14.1 3 F 4 4
44.8 14.3
F-1/2 5 5-1/4
45.5 14.5 3-1/2 G

46.1 14.7
G-1/2 6 6-1/2
46.8 14.9 4 H 7
47.4 15.1
H-1/2
7-3/4
48.0 15.3 4-1/2 I 8
48.7 15.5
J
9
49.3 15.7 5 J-1/2 9
50.0 15.9
K
10
50.6 16.1 5-1/2 K-1/2 10
51.2 16.3
L
11-3/4
51.9 16.5 6 L-1/2 11 12-3/4
52.5 16.7
M 12
53.1 16.9 6-1/2 M-1/2 13 14
53.8 17.1
N

54.4 17.3 7 N-1/2 14 15-1/4
55.1 17.5
O

55.7 17.7 7-1/2 O-1/2 15 16-1/2
56.3 17.9
P

57.0 18.1 8 P-1/2 16 17-3/4
57.6 18.3
Q

58.3 18.5 8-1/2 Q-1/2 17
58.9 18.8
R
19
59.5 19.0 9 R-1/2 18
60.2 19.2
S
20-1/4
60.8 19.4 9-1/2 S-1/2 19
61.4 19.6
T
21-1/2
62.1 19.8 10 T-1/2 20
62.7 20.0
U 21
63.4 20.2 10-1/2 U-1/2 22 22-3/4
64.0 20.4
V

64.6 20.6 11 V-1/2 23
65.3 20.8
W
25
65.9 21.0 11-1/2 W-1/2 24
66.6 21.2
X

67.2 21.4 12 X-1/2 25 27-1/2
67.8 21.6
Y

68.5 21.8 12-1/2 Z 26 28-3/4
69.1 22.0
Z-1/2

69.7 22.2 13
27
70.4 22.4
Z + 1

71.0 22.6 13-1/2


Grit Mesh Micron
100,000 0- 0.5 1/4
60,000 0-1 1/2
14,000 0-2 1
13,000 1-2 1.5
9,000 2-3 2.5
8,000 2-4 3
5,000 2-6 4
4,500 4-6 5
2,800 5-10 7
1,800 6-12 9
1,400 8-20 14
1,200 10-20 15
1,050 12-25 18
800 20-30 25
600 20-40 30
500 30-40 35
325 40-50 45
285 50-60 55
240 60-80 70
225 80-100 90
160 100-120 110
100 120-160 150
Courtesy of 3M™

JIS
Grit
Size
FEPE
P-grade
(Europe)
Grit
ANSI
Grit
Average
Particle
size µm
Trizact 3M
Micron
Symbol Flint
Finishing
Emery
Polishing
Flint Emery SC
Equal Finish
10000     0.6   0.5            
9000     0.8                
8000     1   1            
6000     2   2            
4000     3   3            
3000     4 A5 4           Ultra Fine
2500     5 A6 5            
2000 P2000 1200 6.5                
1500 P1500 1000 9   9            
1200   800 12   12           Super Fine
1000 P1200   15 A16 15             
800   600 16         4/0      
600 P1000   18         3/0      
    500 20 A20 20            
  P800   22         2/0      
500   400 24 A30   10/0   0      
  P600   26 A35              
400 P500 360 30 A40 30            
  P400 320 36 A45   9/0 7/0 1/2     Very Fine
360 P360   41   40            
320   280 44     8/0 6/0        
  P320   46                
280 P280 240 53 A65 50 7/0 5/0 1G     Fine
  P240   60 A80 60            
240 P220 220 66 A90   6/0 4/0 2 Extra Fine    
      70   70            
  P180 180 78 A100 80 5/0 3/0 3      
    150 93 A130 90 4/0 2/0     Fine Medium
  P150   97   100            
    120 116 A160 120 3/0     Fine   Coarse
  P120   127             Medium  
    100 141 A200   2/0         Extra Coarse
  P100   156   150            
  P80 80 195   180 0     Medium Coarse  
  P60 60 264     1/2          
  P50   326             Extra Coarse  
    50 351     1          
  P40 40 420     1-1/2     Coarse    
  P36 36 530     2     Extra Coarse    
  P30 30 630     2-1/2          
  P24 24 728     3          
    20 905     3-1/2          
  P20   984                
  P16 16 1320     4          
  P12   1746                
    12 1842     4-1/2          
INCHES
METRIC
INCHES
METRIC
INCHES
METRIC
FRACTIONAL
DECIMAL
mm
FRACTIONAL
DECIMAL
mm
FRACTIONAL
DECIMAL
mm
. 0.0039 0.1000 . 0.5512 14.0000 . 1.8898 48.0000
. 0.0079 0.2000 9/16 0.5625 14.2875 . 1.9291 49.0000
. 0.0118 0.3000 . 0.5709 14.5000 . 1.9685 50.0000
1/64 0.0156 0.3969 37/64 0.5781 14.6844 2 2.0000 50.8000
. 0.0157 0.4000 . 0.5906 15.0000 . 2.0079 51.0000
. 0.0197 0.5000 19/32 0.5938 15.0813 . 2.0472 52.0000
. 0.0236 0.6000 39/64 0.6094 15.4781 . 2.0866 53.0000
. 0.0276 0.7000 . 0.6102 15.5000 . 2.1260 54.0000
1/32 0.0313 0.7938 5/8 0.6250 15.8750 . 2.1654 55.0000
. 0.0315 0.8000 . 0.6299 16.0000 . 2.2047 56.0000
. 0.0354 0.9000 41/64 0.6406 16.2719 . 2.2441 57.0000
. 0.0394 1.0000 . 0.6496 16.5000 2 1/4 2.2500 57.1500
. 0.0433 1.1000 21/32 0.6563 16.6688 . 2.2835 58.0000
3/64 0.0469 1.1906 . 0.6693 17.0000 . 2.3228 59.0000
. 0.0472 1.2000 43/64 0.6719 17.0656 . 2.3622 60.0000
. 0.0512 1.3000 11/16 0.6875 17.4625 . 2.4016 61.0000
. 0.0551 1.4000 . 0.6890 17.5000 . 2.4409 62.0000
. 0.0591 1.5000 45/64 0.7031 17.8594 . 2.4803 63.0000
1/16 0.0625 1.5875 . 0.7087 18.0000 2 1/2 2.5000 63.5000
. 0.0630 1.6000 23/32 0.7188 18.2563 . 2.5197 64.0000
. 0.0669 1.7000 . 0.7283 18.5000 . 2.5591 65.0000
. 0.0709 1.8000 47/64 0.7344 18.6531 . 2.5984 66.0000
. 0.0748 1.9000 . 0.7480 19.0000 . 2.6378 67.0000
5/64 0.0781 1.9844 3/4 0.7500 19.0500 . 2.6772 68.0000
. 0.0787 2.0000 49/64 0.7656 19.4469 . 2.7165 69.0000
. 0.0827 2.1000 . 0.7677 19.5000 2 3/4 2.7500 69.8500
. 0.0866 2.2000 25/32 0.7813 19.8438 . 2.7559 70.0000
. 0.0906 2.3000 . 0.7874 20.0000 . 2.7953 71.0000
3/32 0.0938 2.3813 51/64 0.7969 20.2406 . 2.8346 72.0000
. 0.0945 2.4000 . 0.8071 20.5000 . 2.8740 73.0000
. 0.0984 2.5000 13/16 0.8125 20.6375 . 2.9134 74.0000
7/64 0.1094 2.7781 . 0.8268 21.0000 . 2.9528 75.0000
. 0.1181 3.0000 53/64 0.8281 21.0344 . 2.9921 76.0000
1/8 0.1250 3.1750 27/32 0.8438 21.4313 3 3.0000 76.2000
. 0.1378 3.5000 . 0.8465 21.5000 . 3.0315 77.0000
9/64 0.1406 3.5719 55/64 0.8594 21.8281 . 3.0709 78.0000
5/32 0.1563 3.9688 . 0.8661 22.0000 . 3.1102 79.0000
. 0.1575 4.0000 7/8 0.8750 22.2250 . 3.1496 80.0000
11/64 0.1719 4.3656 . 0.8858 22.5000 . 3.1890 81.0000
. 0.1772 4.5000 57/64 0.8906 22.6219 . 3.2283 82.0000
3/16 0.1875 4.7625 . 0.9055 23.0000 . 3.2677 83.0000
. 0.1969 5.0000 29/32 0.9063 23.0188 . 3.3071 84.0000
13/64 0.2031 5.1594 59/64 0.9219 23.4156 . 3.3465 85.0000
. 0.2165 5.5000 . 0.9252 23.5000 . 3.3858 86.0000
7/32 0.2188 5.5563 15/16 0.9375 23.8125 . 3.4252 87.0000
15/64 0.2344 5.9531 . 0.9449 24.0000 . 3.4646 88.0000
. 0.2362 6.0000 61/64 0.9531 24.2094 3 1/2 3.5000 88.9000
1/4 0.2500 6.3500 . 0.9646 24.5000 . 3.5039 89.0000
. 0.2559 6.5000 31/32 0.9688 24.6063 . 3.5433 90.0000
17/64 0.2656 6.7469 . 0.9843 25.0000 . 3.5827 91.0000
. 0.2756 7.0000 63/64 0.9844 25.0031 . 3.6220 92.0000
9/32 0.2813 7.1438 1 1.0000 25.4000 . 3.6614 93.0000
. 0.2953 7.5000 . 1.0039 25.5000 . 3.7008 94.0000
19/64 0.2969 7.5406 . 1.0236 26.0000 . 3.7402 95.0000
5/16 0.3125 7.9375 . 1.0433 26.5000 . 3.7795 96.0000
. 0.3150 8.0000 . 1.0630 27.0000 . 3.8189 97.0000
21/64 0.3281 8.3344 . 1.0827 27.5000 . 3.8583 98.0000
. 0.3346 8.5000 . 1.1024 28.0000 . 3.8976 99.0000
11/32 0.3438 8.7313 . 1.1220 28.5000 . 3.9370 100.0000
. 0.3543 9.0000 . 1.1417 29.0000 4 4.0000 101.6000
23/64 0.3594 9.1281 . 1.1614 29.5000 . 4.3307 110.0000
. 0.3740 9.5000 . 1.1811 30.0000 4 1/2 4.5000 114.3000
3/8 0.3750 9.5250 . 1.2205 31.0000 . 4.7244 120.0000
25/64 0.3906 9.9219 1 1/4 1.2500 31.7500 5 5.0000 127.0000
. 0.3937 10.0000 . 1.2598 32.0000 . 5.1181 130.0000
13/32 0.4063 10.3188 . 1.2992 33.0000 . 5.5118 140.0000
. 0.4134 10.5000 . 1.3386 34.0000 . 5.9055 150.0000
27/64 0.4219 10.7156 . 1.3780 35.0000 6 6.0000 152.4000
. 0.4331 11.0000 . 1.4173 36.0000 . 6.2992 160.0000
7/16 0.4375 11.1125 . 1.4567 37.0000 . 6.6929 170.0000
. 0.4528 11.5000 . 1.4961 38.0000 . 7.0866 180.0000
29/64 0.4531 11.5094 1 1/2 1.5000 38.1000 . 7.4803 190.0000
15/32 0.4688 11.9063 . 1.5354 39.0000 . 7.8740 200.0000
. 0.4724 12.0000 . 1.5748 40.0000 8 8.0000 203.2000
31/64 0.4844 12.3031 . 1.6142 41.0000 . 9.8425 250.0000
. 0.4921 12.5000 . 1.6535 42.0000 10 10.0000 254.0000
1/2 0.5000 12.7000 . 1.6929 43.0000 20 20.0000 508.0000
. 0.5118 13.0000 . 1.7323 44.0000 30 30.0000 762.0000
33/64 0.5156 13.0969 1 3/4 1.7500 44.4500 40 40.0000 1016.0000
17/32 0.5313 13.4938 . 1.7717 45.0000 60 60.0000 1524.0000
. 0.5315 13.5000 . 1.8110 46.0000 80 80.0000 2032.0000
35/64 0.5469 13.8906 . 1.8504 47.0000 100 100.0000 2540.0000
Renata UCAR
Energizer
Eveready
Maxell
National
Panasonic
Sony
Toshiba
Varta Rayovac Duracell Philips Bulova Timex Citizen Seiko
301 301 SR43SW V301 301 · · 226 D 280-01 SB-A8
303 303 SR44SW V303 303 · · · A 280-08 SB-A9
309 309 SR754SW V309 303 · · · · · ·
313 313 · V313 313 · · · · 280-06 ·
315 315 SR716SW V315 315 · · 614 HA 280-56 SB-AT
317 317 SR516SW V317 317 · · 616 CA 20-58 SB-AR
319 319 SR527SW V319 319 · · 615 · 280-60 SB-AE/DE
321 321 SR616SW V321 321 D321 · 611 DA 280-73 SB-AF/DF
323 323 · V323 323 · · · C · SB-C3
325 325 · V325 325 · · · · 280-02 SB-C1
329 329 SR731SW V329 329 D329 329 · · · ·
333 333 · · · · · · · · ·
335 335 SR512SW · 335 · · 622 · 280-68 SB-AB
339 339 SR614SW V339 · · · · · · ·
341 341 SR714SW V341 341 · · 627 · · ·
343 343 · V343 343 · · 218 B 280-05 ·
344 344 SR1136SW V344 344 · · 242 · · ·
346 346 SR712SW V346 346 · · 628 · 280-66 SB-DH
350 350 · V350 · D350 · · · · C8
354 354 · V354 354 · · · · · SB-B9
357 357 SR44W V357 357 D357H 357 228 J · SB-BK/EK
361 361 SR721W V361 361 · · · X 280-53 SB-AK/DK
362 362 SR721SW V362 362 D362 362 601 S 280-29 SB-AG
364 364 SR621-SW V364 364 D364 463 602 T 280-34 SB-DG
365 365 SR1116W · · · · · · · ·
366 366 SR1116SW V366 366 · · 608 · 280-46 ·
370 370 SR920W V370 370 · · 620 Z 280-51 SB-BN
371 371 SR920SW V371 371 D371 · 605 · 280-31 SB-AN
373 373 SR916SW V373 373 · · 617 WA 280-45 SB-AJ/DJ
376 376 SR626W · · · · 619 MA · ·
377 377 SR626SW V377 377 D377 377 606 BA 280-39 SB-AW
379 379 SR521SW V379 379 D379 · 618 JA 280-59 SB-AC/DC
381 381 SR1120SW V381 381 · · 317 · 280-27 SB-AS/DS
384 384 SR41SW V384 384 D384 · 247 · 280-18 SB-A1/D1
386 386 SR43W B386 386 D386 386 260 H 280-41 SB-B8
389 389 SR1130W V389 389 D389 389 626 M 280-15 SB-BU
390 390 SR1130SW V390 390 D390 390 603 · 280-24 SB-AU
391 391 SR1120W V391 391 D391 391 609 L 280-30 SB-BS/ES
392 392 SR41W V392 392 D392 392 247B K 280-13 SB-B1
393 393 SR754S V393 393 D393 393 255 F · SB-B3
394 394 SR936SW V394 394 D394 · 625 · · SB-A4
395 395 SR927SW V395 395 D395 · 610 LA 280-48 SB-SP/DP
396 396 SR726W V396 396 D396 396 612 V 280-52 SB-BL
397 397 SR726SW V397 397 D397 · 607 N 280-28 SB-AL
399 399 SR927W V399 399 D399 · 613 W 280-44 SB-BP/EP
44 · · · · · · · · · ·
333 · · · · · · · · · ·
751 · · · · · · · · · ·
LR43 186 LR43 V12GA RW84 LR43 186 · · · ·
LR44 186 LR44 V13GA RW82 LR44 A76 · · 280-904 SB-F9
CR927 · · · · · · · · ·
CR1025 · CR1025 · · · · · · · ·
CR1216 CR/BR1216 CR/BR1216 · BR1216 · · · · · ·
CR1220 CR1220 CR/BR1220 CR1220 · · · · · · SB-T13
CR1225 CR1225 BR1225 · BR1225 · · · · · ·
CR1616 CR/BR1616 CR/BR1616 · BR1616 DL1616 · · · · ·
CR1620 CR1620 CR1620 CR1620 CR1620 DL1620 CR1620 · · 280-208 ·
CR1632 · CR1632 · · · · · · · ·
CR2016 CR/BR2016 CR/BR2016 CR2016 CR/BR2016 DL2016 CR2016 CR2016 FA 280-202/4/6 SB-T11
CR2025 CR2025 CR2025 CR2025 CR2025 DL2025 CR2025 CR2025 NA 280-205 SB-T14
CR2032 CR/BR2032 CR/BR2032 CR2032 CR2032 DL2032 CR2032 · · · SB-T15
CR2320 CR2320 CR/BR2320 · BR2320 · · · · 280-201 ·
CR2325 BR2325 BR2325 · BR2325 · · · · · SB-T12
CR2430 CR2430 CR2430 CR2430 CR2430 DL2430 CR2430 · · · ·
CR2450N · CR2450 · · DL2450 · · · · ·
The length of a strip of metal used to make a ring is not the same as the circumference of the finished ring. As the blank is bent around a mandrel, the interior length reduces (due to compression) and the exterior increases (due to stretching). The proper length of the blank is equip to the average circumference of the ring (interior and exterior circumference). The thickness of the metal used increases the exterior circumference of the ring. The lengths of blanks for common gauges of metal used are shown in Ring Blank Lengths, Part 2 (below).

The templates in the PDF below may be used for quick reference. Place one end of the material to be used at "Start", find the desired ring size and mark the point at which the blank is to be cut. Add 0.5mm to the lengths given if the ring is wider than 4mm.

The measurements in the PDF are reprinted from the book Jeweler's Resource with permission from the author Bruce G. Knuth. The complete book contains many more references of gems, metals, formulas and terminology for jewelers.

Download PDF: Ring Blank Lengths

Ring
Size
Circumference
in mm
2.1mm
12ga.
1.6mm
14ga.
1.3mm
18ga.
1mm
18ga.
0.8mm
20ga.
0.6mm
22ga.
0.5mm
24ga.
1 39.0 45.5 44.2 43.0 42.1 41.5 40.9 40.5
1-1/4 39.6 46.2 44.6 43.6 42.7 42.1 41.5 41.1
1-1/2 40.2 46.9 45.2 44.3 43.3 42.7 42.1 41.8
1-3/4 40.8 47.7 45.8 44.9 44.0 43.3 42.7 42.4
2 41.5 48.0 46.5 45.5 44.6 44.0 43.3 43.0
2-1/4 42.1 48.7 47.1 46.2 45.2 44.6 44.0 43.6
2-1/2 42.7 49.3 47.7 46.8 45.8 45.2 44.6 44.3
2-3/4 43.4 49.9 48.4 47.4 46.5 45.8 45.2 44.9
3 44.0 50.6 49.0 48.0 47.1 46.5 45.8 45.6
3-1/4 44.6 51.2 49.6 48.7 47.7 47.1 46.5 46.2
3-1/2 45.2 51.8 50.2 49.3 48.4 47.7 47.1 46.8
3-3/4 45.9 52.4 50.9 49.9 49.0 48.4 47.7 47.4
4 46.5 53.1 51.5 50.6 49.6 49.0 48.3 48.0
4-1/4 47.1 53.7 52.1 51.2 50.2 49.6 49.0 48.7
4-1/2 47.8 54.3 52.8 51.8 50.9 50.2 49.6 49.3
4-3/4 48.4 55.0 53.4 52.4 51.5 50.9 50.2 49.9
5 49.0 55.6 54.0 53.1 52.1 51.5 50.9 50.6
5-1/4 49.6 56.2 54.6 53.7 52.8 52.1 51.5 51.2
5-1/2 50.3 56.8 55.3 54.3 53.4 52.7 52.1 51.8
5-3/4 50.9 57.5 55.9 55.0 54.0 53.4 52.8 52.4
6 51.5 58.1 56.5 55.6 54.6 54.0 53.4 53.1
6-1/4 52.2 58.7 57.1 56.2 55.3 54.6 54.0 53.7
6-1/2 52.8 59.3 57.8 56.8 55.9 55.3 54.6 54.3
6-3/4 53.4 60.0 58.4 57.5 56.5 55.9 55.3 55.0
7 54.0 60.6 59.0 58.1 57.1 56.5 55.9 55.6
7-1/4 54.7 61.2 59.7 58.7 57.8 57.1 56.5 56.2
7-1/2 55.3 61.9 60.3 59.3 58.4 57.8 57.1 56.8
7-3/4 55.9 62.5 60.9 60.0 59.0 58.4 57.8 57.5
8 56.6 63.1 61.5 60.6 59.7 59.0 58.4 58.1
8-1/4 57.2 63.7 62.2 61.2 60.3 59.7 59.0 58.7
8-1/2 57.8 64.4 62.8 61.9 60.9 60.3 59.7 59.3
8-3/4 58.4 65.0 63.4 62.5 61.5 60.9 60.3 60.0
9 59.1 65.6 64.1 63.1 62.2 61.5 60.9 60.6
9-1/4 59.7 66.3 64.7 63.7 62.8 62.2 61.5 61.2
9-1/2 60.3 66.9 65.3 64.4 63.4 62.8 62.2 61.9
9-3/4 60.9 67.5 65.9 65.0 64.1 63.4 62.8 62.5
10 61.6 68.1 66.6 65.6 64.7 64.1 63.4 63.1
10-1/4 62.2 68.8 67.2 66.3 65.3 64.7 64.1 63.7
10-1/2 62.8 69.4 67.8 66.9 65.9 64.3 64.7 64.4
10-3/4 63.5 70.0 68.5 67.5 66.6 65.9 65.3 65.0
11 64.1 70.7 69.1 68.1 67.2 66.6 65.9 65.6
11-1/4 64.7 71.3 69.7 68.8 67.8 67.2 66.6 66.3
11-1/2 65.3 71.9 70.3 69.4 68.5 67.8 67.2 66.9
11-3/4 66.0 72.5 71.0 70.0 69.1 68.5 67.8 67.5
12 66.6 73.2 71.6 70.7 69.7 69.1 68.5 68.1
12-1/4 67.2 73.8 72.2 71.3 70.3 69.7 69.1 68.8
12-1/2 67.9 74.4 72.8 71.9 71.0 70.3 69.7 69.4
12-3/4 68.5 75.0 73.5 72.5 71.6 71.0 70.3 70.0
13 69.1 75.7 74.1 73.2 72.2 71.6 71.0 70.7