Diamond C SDX312: Step Deck
Specifications, configurations, and buyer fit for the Diamond C SDX312 Step Deck.
The SDX312 is a current Diamond C model. The published specifications below come from the manufacturer’s spec sheet. Confirm the current numbers with your dealer before you buy.
Published Specifications
| GVWR | 30,000-40,000 lb |
|---|---|
| Empty weight | 11,750-13,420 lb |
| Lengths | 48-53 ft (incl. 10 ft step deck) |
| Width | 102 in bed |
| Axles | 3x 12,000 lb Lippert |
| Tires | 14-ply all-steel radial |
| Coupler | Gooseneck |
Triple-axle step-deck gooseneck; 18 in low-profile engineered beam frame; 10 ft step deck with slide-in ramps
Read from the manufacturer's published page on September 25, 2026. Options and model-year changes alter these figures, verify the current sheet with the dealer.
Manufacturer Source
Diamond C listed this model family as active when checked on July 19, 2026. Confirm current specifications, options, and local availability directly with the manufacturer and dealer.
View the official Diamond C SDX312 page →