API 6A flange studs and nuts, lockdown screws and gland nuts, outlet and bonnet bolting, made in Houston to your drawings and specifications.
A 5,000 psi land wellhead and Christmas tree to API 6A: a 13-5/8 in. casing head, a 13-5/8 × 11 in. casing spool and an 11 × 7-1/16 in. tubing head under a 2-9/16 in. single-wing tree. It comes apart from the top down, the way a crew would strip it: at each joint the nuts spin off first, then the joint opens and the ring gasket and loose studs float in the gap. Tree cap, swab valve, wing and choke, studded tee, master valves and adapter, then the side outlet valves, the tubing head and the casing spool, with the lock-down screws backed out and the hangers lifted on the way. The bolting we make is in colour. Press Solid view for a steel model, or Cutaway to see the bores, hangers and ring gaskets inside.
Sixteen 1-5/8 in. × 12-1/2 in. studs on a 23-1/4 in. bolt circle, joining the casing head to the casing spool on the 13-5/8 in. 5,000 psi Type 6BX flange, over a BX-160 ring gasket.
Twelve 1-7/8 in. × 13-3/4 in. studs on a 19 in. bolt circle, on the 11 in. 5,000 psi flange between the casing spool and the tubing head, over an R-54 ring gasket.
Twelve 1-3/8 in. × 10-3/4 in. studs on a 12-1/2 in. bolt circle, on the 7-1/16 in. 5,000 psi flange joining the tubing head to the tree's adapter, over an R-46 ring gasket.
Through the rim of each head's top flange, holding the hanger and its seal down in the bowl, each sealed by a packing gland nut.
Tap-end studs screwed into the spool and head bodies at each 2-1/16 in. outlet, plus eight 7/8 in. × 6 in. studs between each outlet valve and its companion flange, with R-24 ring gaskets.
Eight 1 in. studs on a 7-1/2 in. bolt circle at every 2-9/16 in. 5,000 psi connection up the tree and out along the wing to the choke and flowline, each over an R-27 ring gasket.
Eight per gate valve, on the master, swab and wing valves and the four outlet valves.
The heavy threaded nut on the tree cap, off to rig up wireline above the swab valve.
Threaded hammer nut holding the choke bonnet on, off to change the stem and seat.
API 6A flange studs, nuts and lockdown screws to your drawing. Send us your drawings and material spec.
Request a quote832-446-3442A generic 5,000 psi wellhead and tree, not any maker's design. The flanges, studs, ring gaskets, valve face-to-face lengths and the studded tee follow the API 6A tables; the head, spool, valve and choke body shapes, hangers and casing stubs are illustrative, and the lockdown screw and bonnet stud counts and the tap-end stud lengths are typical. Your drawings govern. We manufacture to your drawings and specifications.
Drawn to API Specification 6A for 5,000 psi working pressure: Type 6B and 6BX flanges and their studs, R and BX ring gaskets, gate valve face-to-face lengths and the studded tee.
© 2026 Innovation Fasteners. This interactive drawing, its 3D models and its code may not be copied, hosted elsewhere, scraped or used to train AI models. Terms of use.