Cast Iron Hex Dumbbells

Details

A hex dumbbell cast as a single piece of iron, head and handle together, then coated. Nothing is welded and nothing is bolted, so there is no joint to loosen and no plate to rattle after a year of being dropped on a hard floor. The number that gets inflated in this category is the weight itself, and it is the easiest thing in a gym to check and the last thing anyone checks. Cast dumbbells routinely run three to ten percent under the figure stamped on the head, because the foundry saves iron on every pour and nobody puts a bell on a scale. Five percent under on a 10 kg bell is 500 grams of iron you paid for and did not get, and on the pair it is a kilogram. The second version of the trick counts the rubber coating into the weight, so a 10 kg bell is 9.4 kg of iron wearing 600 grams of rubber. Ours is stated as the finished bell, coating included, and every single one is weighed after coating on a calibrated Class II platform scale whose calibration is traceable to a NABL-accredited laboratory. Tolerance is one percent, which is honest for sand-cast iron and better than the shelf. Where a bell falls outside nominal but inside tolerance, its actual mass is stamped beside the nominal. The coating is a matt rubber vulcanised on, not a dipped vinyl skin. Vinyl splits at the hex corners and then peels in a sheet. The knurl is cut into the iron underneath the coating, so it stays sharp enough to hold a wet grip.

• Single-piece grey cast iron, head and handle together, no welds and no bolted plates
• Every bell weighed after coating, one percent tolerance, actual mass stamped where it differs
• Weight is the finished bell including coating, not the iron before it
• Vulcanised matt rubber, 3 mm, adhesion tested to ASTM D429, not a dipped vinyl skin
• Cut knurl on the iron under the coating, 32 mm handle, medium depth
• Hex heads, so they will not roll off a bench or a rack
• Sold as a pair. Each listed weight is the weight of ONE bell and you receive two
• Ten year warranty on the casting, two on the coating
• No chrome plating to flake, no sand or cement filler, no cast-in cavity
• Cast iron marks tile and wood. Use a mat. The rubber protects the floor from the iron, not the floor from the impact.