Flange Stud Bolts

Flange Stud Bolts are fully threaded studs with no tap end, passing completely through aligned clearance holes in two mating flanges, with a nut threaded onto each end. This is genuinely symmetric — unlike a tap-end double end stud, neither end is permanently engaged into either flange.

Here is why this matters. Because there’s no permanent engagement anywhere along the stud’s length, the entire clamping preload that compresses the gasket between the two flange faces is carried purely by the stud’s own tensile elongation between the two nuts. This means uniform elongation is what maintains gasket compression, and because a flanged joint typically uses many studs around the bolt circle, achieving uniform elongation, and thus even gasket compression, across all of them requires a specific cross-pattern or star-pattern tightening sequence — tightening opposite or diagonal studs incrementally rather than sequentially around the circle. Tightening sequentially around the circle in a normal single pass causes uneven gasket compression, since each new stud’s tightening slightly relaxes its neighbors, genuinely risking leak paths at the under-compressed points even if every individual stud reaches its correct final torque.

A genuine, honest limitation is worth stating plainly. Correct torque sequence alone doesn’t guarantee even compression if the studs themselves have different effective lengths, thread conditions, or lubrication. Inconsistent friction between studs — some lubricated, some dry, some corroded — causes the same applied torque to produce different actual preload and elongation in each stud, undermining the cross-pattern sequence’s intended uniformity. Buyers should confirm that stud lubrication and friction condition is consistent across the full set, not just rely on correct tightening sequence and the same nominal torque value, to genuinely achieve even gasket compression.

Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our flange stud bolt range is manufactured and verified for thread and mechanical property consistency across every set under our ISO 9001:2015 quality system.