Leaf Chain Dimensions Chart
Leaf chain dimensions per ASME B29.8 (BL series). Quick lacing visuals (2×2, 2×3, 3×4, 4×4, 4×6, 6×6), a numbering guide, and the complete dimensions chart.
What is a Leaf Chain?
Leaf chains use link plates and pins with joints that articulate between adjoining pitches—ideal for lifting, counterweight, and tension-linkage applications.
BL Chain Numbering (Quick Guide)
The prefix is BL. The last digit = link plates in the articulating pitch; the preceding digit = plates in the pin-link pitch; the remaining left digits = number of eighths of an inch in the pitch.
Common Lacing Patterns
2×2 lacing
2×3 lacing
3×4 lacing
4×4 lacing
4×6 lacing
6×6 lacing
General Chain Dimensions (inches)
Leaf Chain Dimensions — ASME B29.8
| Chain No. |
Pitch, in |
Lacing |
Wmax |
Wmax |
Dmax |
Smin |
Hmax |
Tmax |
| BL-422 | — | 2x2 | — | — | — | — | — | — |
| BL-423 | — | 2x3 | — | — | — | — | — | — |
| BL-434 | — | 3x4 | — | — | — | — | — | — |
| BL-444 | 0.500 | 4x4 | — | — | 0.2004 | 0.2016 | 0.475 | 0.082 |
| BL-446 | — | 4x6 | — | — | — | — | — | — |
| BL-466 | — | 6x6 | — | — | — | — | — | — |
| BL-522 | — | 2x2 | — | — | — | — | — | — |
| BL-523 | — | 2x3 | — | — | — | — | — | — |
| BL-534 | — | 3x4 | — | — | — | — | — | — |
| BL-544 | 0.625 | 4x4 | — | — | 0.2346 | 0.2358 | 0.594 | 0.098 |
| BL-546 | — | 4x6 | — | — | — | — | — | — |
| BL-566 | — | 6x6 | — | — | — | — | — | — |
| BL-622 | — | 2x2 | — | — | — | — | — | — |
| BL-623 | — | 2x3 | — | — | — | — | — | — |
| BL-634 | — | 3x4 | — | — | — | — | — | — |
| BL-644 | 0.750 | 4x4 | — | — | 0.3126 | 0.3134 | 0.713 | 0.130 |
| BL-646 | — | 4x6 | — | — | — | — | — | — |
| BL-666 | — | 6x6 | — | — | — | — | — | — |
| BL-822 | — | 2x2 | — | — | — | — | — | — |
| BL-823 | — | 2x3 | — | — | — | — | — | — |
| BL-834 | — | 3x4 | — | — | — | — | — | — |
| BL-844 | 1.000 | 4x4 | — | — | 0.376 | 0.376 | 0.950 | 0.161 |
| BL-846 | — | 4x6 | — | — | — | — | — | — |
| BL-866 | — | 6x6 | — | — | — | — | — | — |
| BL-1022 | — | 2x2 | — | — | — | — | — | — |
| BL-1023 | — | 2x3 | — | — | — | — | — | — |
| BL-1034 | — | 3x4 | — | — | — | — | — | — |
| BL-1044 | 1.250 | 4x4 | — | — | 0.4374 | 0.4386 | 1.188 | 0.193 |
| BL-1046 | — | 4x6 | — | — | — | — | — | — |
| BL-1066 | — | 6x6 | — | — | — | — | — | — |
| BL-1222 | — | 2x2 | — | — | — | — | — | — |
| BL-1223 | — | 2x3 | — | — | — | — | — | — |
| BL-1234 | — | 3x4 | — | — | — | — | — | — |
| BL-1244 | 1.500 | 4x4 | — | — | 0.5004 | 0.5016 | 1.425 | 0.227 |
| BL-1246 | — | 4x6 | — | — | — | — | — | — |
| BL-1266 | — | 6x6 | — | — | — | — | — | — |
| BL-1422 | — | 2x2 | — | — | — | — | — | — |
| BL-1423 | — | 2x3 | — | — | — | — | — | — |
| BL-1434 | — | 3x4 | — | — | — | — | — | — |
| BL-1444 | 1.750 | 4x4 | — | — | 0.5626 | 0.5634 | 1.663 | 0.260 |
| BL-1446 | — | 4x6 | — | — | — | — | — | — |
| BL-1466 | — | 6x6 | — | — | — | — | — | — |
| BL-1622 | — | 2x2 | — | — | — | — | — | — |
| BL-1623 | — | 2x3 | — | — | — | — | — | — |
| BL-1634 | — | 3x4 | — | — | — | — | — | — |
| BL-1644 | 2.000 | 4x4 | — | — | 0.6874 | 0.6886 | 1.9000 | 0.296 |
| BL-1646 | — | 4x6 | — | — | — | — | — | — |
| BL-1666 | — | 6x6 | — | — | — | — | — | — |
| BL-2022 | — | 2x2 | — | — | — | — | — | — |
| BL-2023 | — | 2x3 | — | — | — | — | — | — |
| BL-2034 | — | 3x4 | — | — | — | — | — | — |
| BL-2044 | 2.500 | 4x4 | — | — | 0.9374 | 0.9386 | 2.375 | 0.390 |
| BL-2046 | — | 4x6 | — | — | — | — | — | — |
| BL-2066 | — | 6x6 | — | — | — | — | — | — |
Notes: Dimensions in inches; see ASME B29.8 for complete tolerances and application limits.
Selection Tips
- Choose lacing (e.g., 4×4 vs 4×6) per required load capacity and articulation life.
- Check sheave diameter/groove against Dmax and Hmax to avoid interference.
- Follow manufacturer guidance for pins, clevises, and lubrication.
- For abrasive/outdoor service, specify protective finishes and maintenance intervals.
Reference
- ASME B29.8 — Leaf Chains, Clevises, and Sheaves
Frequently Asked Questions
Which BL lacing should I choose? Higher plate counts (4×6, 6×6) boost capacity but may require larger sheaves.
Is BL the same as LL? No—BL (ASME B29.8) differs from the older LL series. Match the specified standard for your equipment.