FAQ ABOUT HARDWARE AND SOFTGOODS

Products - Hardware & Softgoods

FAQ ABOUT HARDWARE AND SOFTGOODS

There is no visual inspection method to be sure an O-ring is oxygen compatible, only specialized materials testing equipment can make that determination. To ensure oxygen compatibility, O-rings must be specified as oxygen compatible at time of purchase and then segregated from non-compatible O-rings. There are no O-ring color coding standards and thus color or appearance is not an indication of the material or quality. O-rings are available in nearly any color, although most commonly seen in black regardless of material.

Even though most fluorocarbon elastomer (aka FKM, aka FPM, aka Viton) O-rings are black, the loose FKM O-rings sold by Dive Gear Express are oxygen compatible and usually brown or green; simply to make them easily distinguishable from more common acrylonitrile butadiene rubber elastomer (aka NBR, aka Nitrile, aka Buna-N) O-rings which are usually black and not generally considered suitable for oxygen service. However, the oxygen compatible O-rings inside equipment (valves, regulators, hoses, service kits, etc.) are almost always black. O-ring materials also can not be distinguished from each other by their surface appearance, more a function of the manufacturer than the material. NBR is incorrectly said to have a shiny surface and FKM a matte surface. This is not a reliable indicator, and certainly not true if the O-ring has been lubricated.

Just to be clear, the COLOR and SURFACE APPEARANCE of the O-ring is MEANINGLESS regarding their compatibility with oxygen.

Our standard stainless steel cylinder clamps are typical of those widely used in diving applications and will meet the needs of most divers. However, over-tightening most ordinary clamps by applying maximum effort with a hand screwdriver, it is possible to either break the grooves on the band or rupture the worm drive housing. Our tests of the high-torque stainless steel cylinder clamps found no amount of hand screwdriver torque was able to cause them to fail. This does not mean that it is impossible to over-tighten the high-torque versions enough to break the clamp; it is just much more difficult. The disadvantages of the high-torque clamps are the worm drive assembly and band thickness are larger than typical, plus the prices are more than double the prices of the standard clamps.
A common misconception among divers is that stainless steel does not corrode at all. There are various types of stainless steel, each with different corrosion properties, that make a specific grade more or less suited to a particular application. All diving products made of stainless steel must receive some basic care to help minimize corrosion, more information is available in our StainLESS does not mean StainPROOF Tek-Tip.

Yes. Shock cord, surgical tubing, and nylon webbing are all priced and ordered in units of {1 ft | 30 cm}, but we would look pretty foolish if we actually shipped it in little pieces. Orders of cord and webbing up to {50 ft | 15 m} are shipped as one continuous piece. Surgical tubing is different; tubing orders up to {10 ft | 3 m} are shipped as one continuous piece. For example, if you want a continuous length of ten feet or three meters, order ten units.

If you need a large amount of the cord or tubing, we also sell it in bulk rolls at a better price.

Unfortunately, there is no meaningful number we can use to describe the stiffness of our DGX Gears {2 in | 5 cm} harness webbing. The best answer we can give is that our webbing is what we believe to be the "correct amount" of compromise between flexibility and stiffness for the specific application of SCUBA diving BCD harnesses - stiffer than "seat-belt" webbing but less stiff than "tank-strap" webbing. The webbing may seem a little too stiff at first, but once wet and "broken-in" it will be the correct amount of stiffness to hold a shape and be comfortable.

Assembly screws are also called "book screws" or "sex bolts", and are available in both metal and plastic versions. Years ago our suppliers used to include a metal set with their wings and later switched to a plastic set, but have not included either for a long time because assembly screws are often counterproductive.

The plastic assembly screws can be used to attach the wing directly to a hard metal backplate when rigged for a single tank without a single tank adapter. Note that this function is just cosmetic, omitting the assembly screws does not cause a problem. Without the assembly screws, when the BCD is taken off a single tank, the wing will hang loose on the cam straps.

The metal assembly screws can be used to attach accessories to the holes on edges of metal backplates, but in our opinion the plastic ones actually work better. Don't be concerned about the strength of plastic vs metal; the plastic version is plenty strong for these applications plus they are not subject to galvanic action and don't cause wear on materials rubbing against them.