Attaching a Sidemount Cylinder Bolt Snap

Published on by

Attaching a Sidemount Cylinder Bolt Snap

Attaching a Sidemount Cylinder Bolt Snap

There are two common ways to attach the lower bolt snaps to sidemount cylinders – cam bands or stainless steel ring clamps. If you're new to sidemount, the following are brief set up instructions for both methods - I hope you find them useful!

attach with cam band

Using cam bands

Cut a 40cm length of 6mm static cord (you can use thinner cord but it must be strong) and heat seal each end with a match or candle. Pass the cord through the ‘eye’ of the bolt snap and tie the ends together. Alternatively you can tie a knot in each end of the cord; in which case you’ll only need about 34cm of cord.

Position the cord under the cam band / tank band and tighten the strap in the normal manner.

Tip: Position the cam buckle on the back of the cylinder (opposite side from the valve opening) with the end flap pointing away from the diver. This way the buckle and end flap should not interfere with hoses that are stowed between the diver’s body and the cylinder.

Using stainless steel ring clamps

To make a large clamp easier to work with, you may wish to gently tighten the ring clap around the cylinder and cut off the end of the steel band leaving about 4 - 5cm protruding past the fastening screw.

attach with ring clamp

Undo the ring clamp fully and place a 4 – 5cm piece of tubing (about 16mm internal diameter) over the clamp’s screw (this is to protect your hands and wetsuit). You may also thread tubular webbing along the length of the steel band, which avoids scratching painted cylinders. Reconnect the ends of the clamp. Note: ring clamps are also available ready made with tubing and webbing.

Cut a 30cm length of 6mm static cord and heat seal each end. Pass the cord through the ‘eye’ of a bolt snap and tie a knot in each end.

Slide the ring clamp over the cylinder, trapping the knotted ends of the cord on one side and the bolt snap on the other side. The bolt snap can be positioned either above or below the clamp.

Ensure the ring clamp sits level around the cylinder and tighten with the bolt inside the section of tubing with it located over the cord. If you don’t have webbing on the clamp, bend the end of the steel strap inwards to avoid it catching.


The location for bolt snaps will depend on if you are attaching aluminium cylinders to D-rings near your hip or steel cylinders to rear flat rings or a butt plate. It depends on if you are using simple bungee loops or bungees with bolt snaps connecting to shoulder D-rings (the position of the cylinders will change with any 'twist' created when attaching the bungee). It even depends on the length of the cord and bolt snap, and the position of the cam band / ring clamp – so you’ll need to experiment. For steel cylinders attached to the Stealth's rear flat rings, and simple loop bungees, I find it best with the bolt snap lined up with the valve extension post (opposite to the hand wheel).

If you start by using a cam band / tank band attachment, you (or your buddy) can make adjustments underwater until you find the 'right spot'.

The loop of cord connecting the bolt snap should be about 2cm long, out from under the band / clamp, to enable it to move freely and so that you can get your fingers around it when connecting cylinders.

After a trial you may be able to shorten the cords but the above lengths should work to start.


Choosing bolt snaps:

After a trial you may be able to shorten the cords but the above lengths should work to start.

Bolt snaps should be made from marine grade stainless steel (e.g. #316) or brass. 90 to 100mm bolt snaps are common but longer bolt snaps can be easier to handle if wearing gloves.

Some people prefer to put their finger through the bolt snap’s ‘eye’ when clipping cylinders on. In this case, the bolt snap needs a larger sized ‘eye’.


Only registered users may post comments.
Sign in and post comment Register now