Olive (natsume) sinker size chart
Lead and tungsten alloy / sizes 0.2 to 100 gō
In Japan, olive-shaped sliding sinkers (natsume) are sold by gō (号). 1 gō = 3.75 g (one monme, an old Japanese unit), so the weight in grams is the size × 3.75.
The chart lists common sizes with their weight and the approximate dimensions of a sinker of that weight in lead and in tungsten alloy. Dimensions are in mm.
| Size (gō) | Weight (g) | oz | Lead (11.34 g/cm³) | Tungsten alloy (18.0) | |||
|---|---|---|---|---|---|---|---|
| Max dia. | Length | Hole | Max dia. | Length | |||
| #0.2 | 0.75 | 0.026 | 3.8 | 9.6 | 0.5 | 3.2 | 8.3 |
| #0.3 | 1.125 | 0.040 | 4.3 | 11.0 | 0.6 | 3.7 | 9.4 |
| #0.5 | 1.875 | 0.066 | 5.1 | 13.1 | 0.7 | 4.4 | 11.2 |
| #0.8 | 3 | 0.106 | 6.0 | 15.3 | 0.8 | 5.1 | 13.1 |
| #1 | 3.75 | 0.132 | 6.5 | 16.5 | 0.8 | 5.5 | 14.1 |
| #1.5 | 5.625 | 0.198 | 7.4 | 18.8 | 1.0 | 6.3 | 16.2 |
| #2 | 7.5 | 0.265 | 8.1 | 20.7 | 1.1 | 7.0 | 17.8 |
| #2.5 | 9.375 | 0.331 | 8.8 | 22.3 | 1.1 | 7.5 | 19.2 |
| #3 | 11.25 | 0.397 | 9.3 | 23.7 | 1.2 | 8.0 | 20.4 |
| #4 | 15 | 0.529 | 10.3 | 26.1 | 1.3 | 8.8 | 22.4 |
| #5 | 18.75 | 0.661 | 11.0 | 28.1 | 1.4 | 9.5 | 24.1 |
| #6 | 22.5 | 0.794 | 11.7 | 29.9 | 1.5 | 10.1 | 25.6 |
| #7 | 26.25 | 0.926 | 12.4 | 31.5 | 1.6 | 10.6 | 27.0 |
| #8 | 30 | 1.06 | 12.9 | 32.9 | 1.7 | 11.1 | 28.2 |
| #10 | 37.5 | 1.32 | 13.9 | 35.5 | 1.8 | 11.9 | 30.4 |
| #12 | 45 | 1.59 | 14.8 | 37.7 | 1.9 | 12.7 | 32.3 |
| #15 | 56.25 | 1.98 | 15.9 | 40.6 | 2.1 | 13.7 | 34.8 |
| #18 | 67.5 | 2.38 | 16.9 | 43.1 | 2.2 | 14.5 | 37.0 |
| #20 | 75 | 2.65 | 17.5 | 44.7 | 2.3 | 15.0 | 38.3 |
| #25 | 93.75 | 3.31 | 18.9 | 48.1 | 2.4 | 16.2 | 41.3 |
| #30 | 112.5 | 3.97 | 20.1 | 51.1 | 2.6 | 17.2 | 43.8 |
| #35 | 131.25 | 4.63 | 21.1 | 53.8 | 2.7 | 18.1 | 46.2 |
| #40 | 150 | 5.29 | 22.1 | 56.3 | 2.9 | 18.9 | 48.3 |
| #50 | 187.5 | 6.61 | 23.8 | 60.6 | 3.1 | 20.4 | 52.0 |
| #60 | 225 | 7.94 | 25.3 | 64.4 | 3.3 | 21.7 | 55.2 |
| #80 | 300 | 10.58 | 27.8 | 70.9 | 3.6 | 23.9 | 60.8 |
| #100 | 375 | 13.23 | 30.0 | 76.4 | 3.9 | 25.7 | 65.5 |
How the dimensions were calculated
Each row scales the olive sinker shape used in Lure Parts Modeler until it reaches the weight. The shape is a super-ellipse with fullness 1.7, an end face of 0.25 × the max diameter, a length of 2.55 × the max diameter and a hole of about 0.13 × the max diameter. It was fitted to measured commercial sinkers (60 to 100 gō); in lead it matches their weight within about ±3%.
Commercial sinkers differ between makers and processes, and small sizes often have a relatively larger hole. Measure a real sinker if you need exact dimensions, for example to make a mold.
Lead vs tungsten
Tungsten alloy is about 1.6 times as dense as lead, so the same weight is smaller. At 3 gō (11.25 g) the max diameter drops from 9.3 mm to 8.0 mm, about 14% thinner, and the volume is about 37% smaller. A smaller sinker has less drag, snags less and transmits bites better, but the material costs more.
Weight in water
A sinker feels lighter in water by the weight of the water it displaces. Lead loses about 8.8% in fresh water and 9.0% in sea water; tungsten alloy about 5.6% and 5.7%. See Metal densities and underwater weight for lure parts.
Make it in Lure Parts Modeler →Pick a size and get a 3D model (STEP, STL and more) of an olive sinker of exactly that weight. Change the material and the dimensions are recalculated.