Posted by Advantage Rigging on 30th Oct 2026
Screw Pin Shackles: Sizes, Ratings and Safe Use
What is a screw pin shackle?
A screw pin shackle is a U-shaped (bow) steel connector closed by a pin that screws into one ear. It joins slings, hooks, chain, wire rope and lifting points, and the pin can be taken out and put back by hand, which makes it the quick choice for rigging that is put together and taken apart often.
Anchor (bow) or chain (D) shackle?
An anchor shackle has a rounded bow with more room inside. It suits connecting more than one sling, and loads that pull at an angle within the shackle's rated limits. A chain shackle (D shackle) has a narrow, straight body for a single in-line pull. The screw pin shackles in our store are anchor style.
Screw pin or bolt type?
A screw pin is fast to install and remove, and suits temporary rigging where the pin can't roll under load. A bolt type (round pin with a nut and cotter pin) is for long-term or permanent rigging, or wherever the load or line could turn the pin and unscrew it.
Screw pin shackle sizes and working load limits
| Shackle size | WLL (tons) |
|---|---|
| 5/16" | 0.75 |
| 3/8" | 1 |
| 7/16" | 1.5 |
| 1/2" | 2 |
| 5/8" | 3.25 |
| 3/4" | 4.75 |
| 7/8" | 6.5 |
| 1" | 8.5 |
| 1-1/8" | 9.5 |
| 1-1/4" | 12 |
| 1-3/8" | 13.5 |
| 1-1/2" | 17 |
| 1-3/4" | 25 |
| 2" | 35 |
The size is the diameter of the bow steel. The WLL is marked on each shackle; always follow it and the manufacturer's reductions for side loading.
Using screw pin shackles safely
- Screw the pin in all the way, so its collar seats against the shackle ear. Never replace the pin with a bolt.
- Load the shackle in line with its centerline. Side loading lowers the rating; check the manufacturer's reduction chart.
- If the line or load can move or rotate against the pin, use a bolt-type shackle so the pin can't unscrew.
- Take a shackle out of service if it is bent, cracked, worn, heat damaged, if the pin doesn't thread in fully, or if the WLL marking can't be read.
Shop screw pin shackles from 5/16" to 2", or call 480-502-2225 for help picking the right size. Related: OSHA rigging hardware requirements.