In addition to Standard Precision Roller Chain, Maryland Metrics also imports Heavy Series Roller Chain built in accordance with JB 3876 and ANSI B29.1. Heavy Series Roller Chain is not necessarily stronger than Standard Series Roller Chain. However, the thicker link plate provides an increase in fatigue resistance for those drives subjected to heavy shock loads, multiple stops/starts or reversing.
| ANSI Chain No. | Pitch | Roller Diameter | Width Between Inner Plates | Transverse Pitch | Chain Path Depth | Plate Thickness | Breaking Load (daN) | |||
| in | mm | Simplex | Duplex | Triplex | ||||||
| 60H | 3/4 | 19.05 | 11.91 | 12.57 | 26.11 | 18.34 | 3.18 | 3110 | 6230 | 9340 |
| 80H | 1 | 25.40 | 15.88 | 15.75 | 32.59 | 24.39 | 3.96 | 5560 | 11120 | 16680 |
| 100H | 1 1/4 | 31.75 | 19.05 | 18.60 | 39.09 | 30.48 | 4.75 | 8670 | 17350 | 26020 |
| 120H | 1 1/2 | 38.10 | 22.23 | 25.22 | 48.87 | 36.55 | 5.56 | 12460 | 24910 | 37370 |
| 140H | 1 3/4 | 44.45 | 25.40 | 25.22 | 52.2 | 42.67 | 6.35 | 16900 | 33810 | 50710 |
| 160H | 2 | 50.80 | 28.58 | 31.55 | 61.90 | 48.74 | 7.14 | 22240 | 44480 | 66720 |
| 180H | 2 1/4 | 57.15 | 35.71 | 35.49 | 69.16 | 54.6 | 7.92 | 28130 | 56260 | 84390 |
| 200H | 2 1/2 | 63.50 | 39.68 | 37.85 | 78.13 | 60.93 | 9.52 | 34700 | 69390 | 104090 |
| 240H | 3 | 76.20 | 47.63 | 47.35 | 101.22 | 73.13 | - | 500300 | 1000600 | 1500900 |