Gauge Block Calculator
Calculate precise gauge block stack heights for sine bar setups. Get the target height from any angle with 4-decimal accuracy.
✓ Height from angle calculation
✓ 0.0001” precision
✓ Inch and metric support
Degrees, minutes, seconds
Gage Block Height
2.5000 in
= 63.5000 mm
Quick reference — Gage block heights (inches)
| Angle | 5″ bar | 10″ bar |
|---|---|---|
| 5° | 0.4358 | 0.8716 |
| 10° | 0.8682 | 1.7365 |
| 15° | 1.2941 | 2.5882 |
| 20° | 1.7101 | 3.4202 |
| 25° | 2.1131 | 4.2262 |
| 30° | 2.5000 | 5.0000 |
| 35° | 2.8679 | 5.7358 |
| 40° | 3.2139 | 6.4279 |
| 45° | 3.5355 | 7.0711 |
Gauge Block Stacking for Sine Bars
Gauge blocks (also called gage blocks or Jo blocks) are precision-ground steel or ceramic blocks used to build exact heights. When combined with a sine bar, they allow you to create any angle to within seconds of arc.
How to Build a Stack
The goal is to reach your target height using the fewest blocks possible (each wringing junction adds ~0.000005” uncertainty):
Target: 1.3862”
1. Pick 0.1002” (eliminates the last digit: 2)
2. Remaining: 1.2860” — pick 0.136”
3. Remaining: 1.1500” — pick 0.150”
4. Remaining: 1.0000” — pick 1.000”
Stack: 1.000 + 0.150 + 0.136 + 0.1002 = 1.3862” (4 blocks)
Standard Gauge Block Sets
- 36-piece set: Basic shop use, covers most common heights
- 81-piece set: Most popular, can reach any height in 0.0001” increments
- 112-piece set: Extended range with more size options
Best Practices
- Use the minimum number of blocks — fewer joints = less uncertainty
- Wring blocks properly: Clean, slide together at 90°, then rotate to align
- Never force blocks — if they don't wring smoothly, they need cleaning
- Store in climate-controlled environment; temperature affects steel gauge block dimensions
🔧 Maintenance Note
Gauge blocks should be calibrated annually for inspection use. Deburr any nicks immediately — even microscopic damage affects wringing quality and dimensional accuracy.