Double End Stud Bolts

A double end stud bolt has threads on both ends and no head. One end, the tap end, is installed permanently into a tapped hole and typically never removed. The other end, the nut end, receives a nut that is removed and reinstalled during routine maintenance.

Here is why this matters. Because the tap end stays permanently engaged, all the wear from repeated disassembly and reassembly during maintenance happens on the replaceable nut and the stud’s own free-end threads — not on the vessel or flange body’s own tapped hole. This genuinely protects the tapped hole, which is expensive and often impractical to re-tap or repair, from the thread wear that would occur if a bolt were repeatedly removed and reinstalled directly into that same hole. This is precisely why studs, not bolts, are the standard choice for flanged joints and pressure vessel connections that are opened and closed repeatedly over the equipment’s service life.

A genuine, honest limitation is worth stating plainly. Because the tap end’s engagement is intended to be permanent, if the tap end is ever damaged — cross-threaded, corroded, or the tapped hole itself compromised — removing a properly installed stud is genuinely more difficult than removing a bolt, precisely because it wasn’t designed for routine removal. Proper installation torque and thread engagement at the tap end, verified at the time of installation, is genuinely more critical for a stud than for a bolt, since a poorly installed stud may need to be drilled out or otherwise destructively removed if it later needs replacement.

Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our double end stud bolt range is manufactured and verified for thread and mechanical property compliance under our ISO 9001:2015 quality system.