Side-bow chain
Flexes sideways as well as around the sprocket, so your conveyor can turn, climb and curve without tearing the chain apart.
When the conveyor won't run in a straight line
Standard roller chain articulates in one plane only. Force it round a bend and it binds, wears the guides and tears itself apart. Side-bow chain is built with extra clearance in the joint, so it flexes sideways as well as around the sprocket. It follows curved, inclined and three-dimensional conveyor paths without fighting the track.
It is the chain behind curved accumulation lines, S-bend transfers, spiral conveyors and any layout where the product must change direction without leaving the chain.
Sizes & minimum curve radii
The curve radius is the number that matters. It is the tightest bend the chain will follow without binding.
| Chain | Pitch (mm) | Inner width (mm) | Roller Ø (mm) | Min curve radius (mm) | Breaking load (kgf, ave.) | Weight (kg/m) |
|---|---|---|---|---|---|---|
| 35SB | 9.525 | 4.68 | 5.08 | 254 | 900 | 0.32 |
| 40SB | 12.70 | 7.85 | 7.92 | 350 | 1,600 | 0.60 |
| 40NSB | 12.70 | 7.85 | 7.92 | 320 | 1,300 | 0.50 |
| 08BSB | 12.70 | 7.75 | 8.51 | 350 | 1,600 | 0.63 |
| 50SB | 15.875 | 9.42 | 10.16 | 400 | 1,700 | 0.99 |
| 60SB | 19.05 | 12.57 | 11.91 | 400 | 2,700 | 1.40 |
| 603SB | 19.05 | 12.57 | 11.91 | 400 | 2,700 | 1.46 |
| 63SB | 19.05 | 12.57 | 11.91 | 400 | 2,700 | 1.39 |
| 08BSBSS | 12.70 | 7.75 | 8.51 | 350 | — | 0.63 |
| 50SBSS | 15.875 | 9.42 | 10.16 | 400 | — | 0.99 |
| 63SBSS | 19.05 | 12.57 | 11.91 | 400 | — | 1.39 |
Stainless steel versions (SS suffix) available for washdown and corrosive lines. 63SB is built with extended pins to carry plastic flights, making a side-flexing table chain. Attachments and connecting links to suit. ANSI 35, 40 and 60 side-bow is held in UK stock with connecting links to suit; other sizes and stainless steel are supplied to order — contact us for current lead time.
What we need to know
Side-bow selection is about geometry as much as load. Tell us:
- The tightest curve radius on the line; the chain's minimum curve radius must be smaller than it
- Whether the bend is horizontal, vertical, or both
- Chain speed and the load being carried
- The environment: stainless steel for washdown, coated for damp
- Any flights, slats or attachments the chain must carry
Curved packaging and accumulation lines · spiral conveyors · S-bend transfers between machines · three-dimensional layouts in tight plant rooms · side-flexing table-top conveyors (63SB with plastic flights).
Straight answers
What is side-bow chain?
A roller chain built with extra clearance in the joints so it can flex sideways as well as bend around the sprocket. It lets a conveyor follow curved, inclined or three-dimensional paths that would bind and destroy standard roller chain.
What curve radius can side-bow chain follow?
It depends on the size: from 254 mm on the smallest 35SB up to around 400 mm on the larger 50SB, 60SB and 63SB chains. The minimum curve radius is a hard limit; the chain must be selected for the tightest bend on your line.
Can side-bow chain carry flights or slats?
Yes. The 63SB is made with extended pins specifically to hold plastic flights, creating a side-flexing table chain. Other attachments can be built to your drawing.
Conveyor that has to turn a corner?
Send us the layout, the tightest radius and the load, and we will specify the chain that will follow it.