Gauge block stack calculator
45.6785 mm from a 112-piece set takes five blocks: 1.0005 + 1.008 + 1.17 + 17.5 + 25. Choose your set and enter the size for the fewest blocks that make it, every block shown on the stack to scale, with wear blocks at both ends if you use them. Sets sold under the same count in two forms (47 and 32 pieces) are listed separately.
- Blocks
- Number of blocks
- 5
- Stack length L
- Another way
- 1.0005 + 1.008 + 1.17 + 24.5 + 18
How it’s calculated
Every combination of the set’s blocks, each used once, is searched for the fewest that sum to the size, after the two wear blocks are taken off. It agrees with the makers’ method: take the block that clears the last decimal place, then the next place, working left, and make up the rest with the large blocks. Where several stacks use as few blocks, vary the large ones so the set wears evenly.
Gauge block sets
| Set | Blocks | Sold as |
|---|---|---|
| 122 pieces mm | 1.0005 · 1.001 to 1.009 by 0.001 (9) · 1.01 to 1.49 by 0.01 (49) · 1.6 to 1.9 by 0.1 (4) · 0.5 to 24.5 by 0.5 (49) · 25 · 30 to 100 by 10 (8) · 75 | Mitutoyo 516-596 to 599, TESA M122, Insize 4100-122, KCP M 122 |
| 112 pieces mm | 1.0005 · 1.001 to 1.009 by 0.001 (9) · 1.01 to 1.49 by 0.01 (49) · 0.5 to 24.5 by 0.5 (49) · 25 to 100 by 25 (4) | Mitutoyo 516-937 to 940, TESA M112, Insize 4100-112, Starrett RS 112.M, KCP M 112 |
| 103 pieces mm | 1.005 · 1.01 to 1.49 by 0.01 (49) · 0.5 to 24.5 by 0.5 (49) · 25 to 100 by 25 (4) | Mitutoyo 516-941 to 944, Insize 4100-103 |
| 88 pieces mm | 1.0005 · 1.001 to 1.009 by 0.001 (9) · 1.01 to 1.49 by 0.01 (49) · 0.5 to 9.5 by 0.5 (19) · 10 to 100 by 10 (10) | Mitutoyo 516-969 to 972, TESA M88, Insize 4100-188, Starrett RS 88.M, KCP M 88 |
| 87 pieces mm | 1.001 to 1.009 by 0.001 (9) · 1.01 to 1.49 by 0.01 (49) · 0.5 to 9.5 by 0.5 (19) · 10 to 100 by 10 (10) | Mitutoyo 516-945 to 948, Mahr 406, Insize 4100-187, Star Tool 224 |
| 76 pieces mm | 1.005 · 1.01 to 1.49 by 0.01 (49) · 0.5 to 9.5 by 0.5 (19) · 10 to 40 by 10 (4) · 50 to 100 by 25 (3) | Mitutoyo 516-949 to 952, Insize 4100-176 |
| 56 pieces mm | 0.5 · 1.001 to 1.009 by 0.001 (9) · 1.01 to 1.09 by 0.01 (9) · 1.1 to 1.9 by 0.1 (9) · 1 to 24 by 1 (24) · 25 to 100 by 25 (4) | Mitutoyo 516-953 to 956, Insize 4100-156 |
| 47 pieces (1 to 24) mm | 1.005 · 1.01 to 1.09 by 0.01 (9) · 1.1 to 1.9 by 0.1 (9) · 1 to 24 by 1 (24) · 25 to 100 by 25 (4) | Mitutoyo 516-957 to 960, TESA M47, Insize 4100-147A |
| 47 pieces (tens) mm | 1.005 · 1.01 to 1.19 by 0.01 (19) · 1.2 to 1.9 by 0.1 (8) · 1 to 9 by 1 (9) · 10 to 100 by 10 (10) | Mitutoyo 516-961 to 964, Insize 4100-147 |
| 46 pieces mm | 1.001 to 1.009 by 0.001 (9) · 1.01 to 1.09 by 0.01 (9) · 1.1 to 1.9 by 0.1 (9) · 1 to 9 by 1 (9) · 10 to 100 by 10 (10) | Mitutoyo 516-994 to 997, Mahr 404, Insize 4100-146 |
| 34 pieces mm | 1.0005 · 1.001 to 1.009 by 0.001 (9) · 1.01 to 1.09 by 0.01 (9) · 1.1 to 1.9 by 0.1 (9) · 1 to 5 by 1 (5) · 10 | Mitutoyo 516-128 to 131, Insize 4100-134 |
| 32 pieces (to 60) mm | 1.005 · 1.01 to 1.09 by 0.01 (9) · 1.1 to 1.9 by 0.1 (9) · 1 to 9 by 1 (9) · 10 to 30 by 10 (3) · 60 | Mitutoyo 516-965 to 968, TESA M32, KCP M 32 |
| 32 pieces (to 50) mm | 1.005 · 1.01 to 1.09 by 0.01 (9) · 1.1 to 1.9 by 0.1 (9) · 1 to 9 by 1 (9) · 10 to 30 by 10 (3) · 50 | Mahr 402, Insize 4100-132 |
| 81 pieces in | .1001 to .1009 by .0001 (9) · .101 to .149 by .001 (49) · .050 to .950 by .050 (19) · 1.000 to 4.000 by 1.000 (4) | Mitutoyo 516-901 to 904, Starrett-Webber RS 81, Star Tool 224 |
| 36 pieces in | .050 · .1001 to .1009 by .0001 (9) · .101 to .109 by .001 (9) · .110 to .190 by .010 (9) · .100 to .500 by .100 (5) · 1.000 · 2.000 · 4.000 | Starrett-Webber SS 36, Fowler 53-670-036, Star Tool |
| 28 pieces (thin) in | .02005 · .0201 to .0209 by .0001 (9) · .021 to .029 by .001 (9) · .010 to .090 by .010 (9) | Mitutoyo 516-917 to 920, Starrett-Webber RS 28 |
How do you choose gauge blocks for a size?
Work from the last decimal place. Take the block that clears the finest digit of the size, subtract it, then the block that clears the next digit, and so on until what is left is a whole number the large blocks make. For 45.6785 mm: 1.0005 leaves 44.678, 1.008 leaves 43.67, 1.17 leaves 42.5, and 17.5 and 25 make the rest. Fewer blocks means fewer errors added together and fewer wrung joints, so the calculator searches every combination for the fewest. If you use wear blocks, take both off the size first: they go one at each end.