Stud Bolt Weight Chart in Kg and Lbs (Metric and Imperial, ASME B16.5)

Look up the weight of a stud bolt online and you will usually find one unlabelled number. The trouble is that a stud bolt weight chart can mean two different things: the weight of the bare, threadedstud bolt alone, or the weight of that same stud fully assembled with two heavy hex nuts, the way it is actually supplied and installed on a flanged joint. Confusing the two is the single most common source of error in stud bolt weight figures published online, and it can throw a buyer’s material take-off or freight estimate off by close to double. This chart gives both figures side by side, clearly labelled, and derived from a stated formula rather than copied from another source. Sizes and lengths below follow standard stud dimensions consistent with the ASME B16.5 flange bolting schedule referenced in Jade Alloys’ ownstud bolt chart, so the length values used for weight here match the length values used for sizing there

What This Chart Shows

A stud bolt is a fully threaded rod, threaded along its entire length or with a short unthreaded shank in the middle, used with two nuts one at each flange face to join two flanges together per ASME B16.5. Because the finished, in-service joint always uses a stud plus two nuts, but a purchase order or bill of quantities is often costed on bare stud material alone, the tables below give both figures: Stud Bolt Only weight, and Stud Bolt with 2 Heavy Hex Nuts weight, so the reader can pick whichever one matches what they are actually ordering..

How Stud Bolt Weight Is Calculated

Every figure in this chart is calculated the same way, using the standard volume times density approach adjusted for the reduced cross section along a stud’s threaded length:

Weight (kg) = Diameter² (mm) × Length (mm) × 0.00000617 × 0.855

Here, 0.00000617 is derived from π ⁄ 4 × steel density (7.85 g per cubic cm for carbon steel), and 0.855 is the standard allowance for the reduced cross section along the threaded portion of the stud, since a threaded rod weighs measurably less than a plain round bar of the same nominal diameter and length. Stainless steel studs (density approximately 7.9 to 8.0 g per cubic cm, against 7.85 for carbon steel) run roughly 1 to 2 percent heavier than a carbon steel stud of the same size; see the note further down this page.

Stud Bolt Weight Chart, Imperial (Kg)

Stud Bolt Only Weight Chart, Metric (Kg)

Carbon Steel vs Stainless Steel Weight Difference

Every table above is calculated for carbon steel (7.85 g/cm³). A stainless steel stud of the same nominal diameter and length, such as anA2-70 stainless steel bolt, will weigh roughly 1 to 2 percent more, purely because austenitic stainless (7.9 to 8.0 g/cm³) is slightly denser than carbon steel, not because of any dimensional difference. This is a small enough gap that it rarely changes a freight estimate meaningfully, but it matters for precise mill weight reconciliation. Readers sourcing stainless studs specifically may also find theASTM A193 B7 andASTM A320 L7 grade pages useful for material selection alongside weight.

Frequently Asked Questions