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Bar Joist Size Database
Browse SJI K-series and LH longspan designations for depth, approximate weight, and standard seat depth — handy when coordinating joist seats with girders and deck.
Bar Joist Browser
SJI Standard Designations & Properties
Showing all 118 designations.
K-Series (Standard Open Web Joists)
Depths from 10 in to 30 in with a 2.5 in standard seat. The chord number after the K raises capacity at a fixed depth: a 16K9 and a 16K2 both measure 16 in deep, but the 16K9 weighs almost twice as much. 63 designations tabulated.
| Designation | Total depth in |
Approx. weight plf |
Standard seat in |
|---|---|---|---|
| 10K1 | 10 | 5.0 | 2.5 |
| 12K1 | 12 | 5.0 | 2.5 |
| 12K3 | 12 | 5.7 | 2.5 |
| 12K5 | 12 | 7.1 | 2.5 |
| 14K1 | 14 | 5.2 | 2.5 |
| 14K3 | 14 | 6.0 | 2.5 |
| 14K4 | 14 | 6.7 | 2.5 |
| 14K6 | 14 | 7.7 | 2.5 |
| 16K2 | 16 | 5.5 | 2.5 |
| 16K3 | 16 | 6.3 | 2.5 |
| 16K4 | 16 | 7.0 | 2.5 |
| 16K5 | 16 | 7.5 | 2.5 |
| 16K6 | 16 | 8.1 | 2.5 |
| 16K7 | 16 | 8.6 | 2.5 |
| 16K9 | 16 | 10.0 | 2.5 |
| 18K3 | 18 | 6.4 | 2.5 |
| 18K4 | 18 | 7.2 | 2.5 |
| 18K5 | 18 | 7.7 | 2.5 |
| 18K6 | 18 | 8.4 | 2.5 |
| 18K7 | 18 | 8.9 | 2.5 |
| 18K9 | 18 | 10.1 | 2.5 |
| 18K10 | 18 | 11.6 | 2.5 |
| 20K3 | 20 | 6.5 | 2.5 |
| 20K4 | 20 | 7.2 | 2.5 |
| 20K5 | 20 | 7.7 | 2.5 |
| 20K6 | 20 | 8.4 | 2.5 |
| 20K7 | 20 | 8.9 | 2.5 |
| 20K9 | 20 | 10.1 | 2.5 |
| 20K10 | 20 | 11.6 | 2.5 |
| 22K4 | 22 | 7.3 | 2.5 |
| 22K5 | 22 | 7.7 | 2.5 |
| 22K6 | 22 | 8.5 | 2.5 |
| 22K7 | 22 | 9.0 | 2.5 |
| 22K9 | 22 | 10.2 | 2.5 |
| 22K10 | 22 | 11.7 | 2.5 |
| 22K11 | 22 | 11.9 | 2.5 |
| 24K4 | 24 | 7.8 | 2.5 |
| 24K5 | 24 | 7.9 | 2.5 |
| 24K6 | 24 | 8.5 | 2.5 |
| 24K7 | 24 | 9.0 | 2.5 |
| 24K8 | 24 | 9.4 | 2.5 |
| 24K9 | 24 | 10.3 | 2.5 |
| 24K10 | 24 | 11.7 | 2.5 |
| 24K12 | 24 | 13.5 | 2.5 |
| 26K5 | 26 | 8.1 | 2.5 |
| 26K6 | 26 | 8.6 | 2.5 |
| 26K7 | 26 | 9.2 | 2.5 |
| 26K8 | 26 | 9.7 | 2.5 |
| 26K9 | 26 | 10.4 | 2.5 |
| 26K10 | 26 | 11.9 | 2.5 |
| 26K12 | 26 | 13.6 | 2.5 |
| 28K6 | 28 | 8.8 | 2.5 |
| 28K7 | 28 | 9.3 | 2.5 |
| 28K8 | 28 | 9.8 | 2.5 |
| 28K9 | 28 | 10.6 | 2.5 |
| 28K10 | 28 | 12.0 | 2.5 |
| 28K12 | 28 | 13.8 | 2.5 |
| 30K7 | 30 | 9.6 | 2.5 |
| 30K8 | 30 | 10.0 | 2.5 |
| 30K9 | 30 | 10.6 | 2.5 |
| 30K10 | 30 | 11.9 | 2.5 |
| 30K11 | 30 | 13.3 | 2.5 |
| 30K12 | 30 | 15.0 | 2.5 |
LH-Series (Longspan Joists)
Depths from 18 in to 48 in with a 5.0 in standard seat. Heavier LH chords sometimes ship with a 7.5 in seat, so confirm the seat before you set girder top-of-steel elevation. 55 designations tabulated.
| Designation | Total depth in |
Approx. weight plf |
Standard seat in |
|---|---|---|---|
| 18LH02 | 18 | 10.0 | 5.0 |
| 18LH03 | 18 | 11.0 | 5.0 |
| 18LH04 | 18 | 12.0 | 5.0 |
| 18LH05 | 18 | 15.0 | 5.0 |
| 18LH06 | 18 | 15.0 | 5.0 |
| 20LH02 | 20 | 10.0 | 5.0 |
| 20LH03 | 20 | 11.0 | 5.0 |
| 20LH04 | 20 | 12.0 | 5.0 |
| 20LH05 | 20 | 15.0 | 5.0 |
| 20LH06 | 20 | 15.0 | 5.0 |
| 20LH07 | 20 | 17.0 | 5.0 |
| 24LH03 | 24 | 11.0 | 5.0 |
| 24LH04 | 24 | 12.0 | 5.0 |
| 24LH05 | 24 | 13.0 | 5.0 |
| 24LH06 | 24 | 16.0 | 5.0 |
| 24LH07 | 24 | 17.0 | 5.0 |
| 24LH08 | 24 | 18.0 | 5.0 |
| 24LH09 | 24 | 21.0 | 5.0 |
| 24LH10 | 24 | 23.0 | 5.0 |
| 28LH05 | 28 | 13.0 | 5.0 |
| 28LH06 | 28 | 16.0 | 5.0 |
| 28LH07 | 28 | 17.0 | 5.0 |
| 28LH08 | 28 | 18.0 | 5.0 |
| 28LH09 | 28 | 21.0 | 5.0 |
| 28LH10 | 28 | 23.0 | 5.0 |
| 28LH12 | 28 | 27.0 | 5.0 |
| 32LH06 | 32 | 14.0 | 5.0 |
| 32LH07 | 32 | 16.0 | 5.0 |
| 32LH09 | 32 | 21.0 | 5.0 |
| 32LH10 | 32 | 21.0 | 5.0 |
| 32LH12 | 32 | 27.0 | 5.0 |
| 32LH13 | 32 | 30.0 | 5.0 |
| 32LH15 | 32 | 35.0 | 5.0 |
| 36LH07 | 36 | 16.0 | 5.0 |
| 36LH09 | 36 | 21.0 | 5.0 |
| 36LH10 | 36 | 21.0 | 5.0 |
| 36LH11 | 36 | 23.0 | 5.0 |
| 36LH13 | 36 | 30.0 | 5.0 |
| 36LH15 | 36 | 36.0 | 5.0 |
| 40LH08 | 40 | 16.0 | 5.0 |
| 40LH10 | 40 | 21.0 | 5.0 |
| 40LH12 | 40 | 25.0 | 5.0 |
| 40LH14 | 40 | 35.0 | 5.0 |
| 40LH16 | 40 | 42.0 | 5.0 |
| 44LH09 | 44 | 19.0 | 5.0 |
| 44LH10 | 44 | 21.0 | 5.0 |
| 44LH13 | 44 | 30.0 | 5.0 |
| 44LH15 | 44 | 36.0 | 5.0 |
| 44LH17 | 44 | 47.0 | 5.0 |
| 48LH10 | 48 | 21.0 | 5.0 |
| 48LH11 | 48 | 22.0 | 5.0 |
| 48LH13 | 48 | 29.0 | 5.0 |
| 48LH14 | 48 | 32.0 | 5.0 |
| 48LH16 | 48 | 42.0 | 5.0 |
| 48LH17 | 48 | 47.0 | 5.0 |
No joists match that designation.
SJI Joist Designations and Seats
Open-web steel joists are ordered by SJI designation — for example 16K4 means 16″ deep, K-series, chord section 4. Higher chord numbers carry more load at a given depth. LH (longspan) joists cover longer bays with deeper seats. This browser helps detailers confirm depth, approximate weight, and the seat depth that must clear on the supporting girder or masonry pocket.
How to use this browser
- Both series are tabulated in full on this page, so you can scan depth against weight without searching first.
- Search by designation (16K4, 24LH05) or click a series button to isolate K-series or LH-series.
- Coordinate seat depth with bearing length, fireproofing, and deck profile before releasing joist reactions to the fabricator.
Seat depths that catch shops off guard
Standard K-series seats are typically 2.5″ deep; LH seats are usually 5.0″ (some heavy LH chords use 7.5″). Calling a K seat into an LH pocket — or forgetting the seat when setting girder elevation — creates field shims and RFI delays. Always confirm special seats, extensions, and bridging with the joist manufacturer’s approval drawings.
FAQ
Is weight exact for shipping?
Listed weights are approximate estimating values. Final weights come from the joist manufacturer’s bill of materials.
Does a higher chord number always mean a deeper joist?
No. Depth is the leading number. Chord number changes capacity within that depth family.
Can I select joists from weight alone?
No. Span, load, bridging, and vibration criteria govern. Use SJI load tables or manufacturer software for selection; use this page for designation/seat coordination.
What about joist girders (G series)?
Joist girders are a separate product line with different designation rules. This database focuses on K and LH bar joists.
Where this fits in the workflow
- AISC Steel Shape Database Pull the supporting girder depth the joist seat has to land on.
- Mezzanine Beam Size Calculator Size the beam carrying the joist reactions.
- Paint & Weight Takeoff Add joist tonnage into the paint and shipping estimate.
Read the longer write-up
- Crane Runway Deflection: L/450 vs L/600 for Estimators Deflection often governs light industrial runway beams before bending stress does. What CMAA-style limits mean for preliminary sizing and shape selection.
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