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Bolts · GB/T 901 / DIN 939 · Application guide

What Are Equal-End Stud Bolt Used For?

Typical applications, the industries that specify equal-end stud bolt, and how to choose the right size, material and finish for the joint.

Equal-End Stud Bolts are used for clamping a joint from both ends where a headed bolt cannot be used, tightened by the nuts rather than by the fastener itself. They are manufactured to GB/T 901 / DIN 939, and the choice of size, property class and finish is driven by the load in the joint and the environment it sits in.

Primary duty
Clamping a joint from both ends where a headed bolt cannot be used, tightened by the nuts rather than by the fastener itself
Governing standard
GB/T 901 / DIN 939
Thread size range
M6 to M36
Category
Bolts

Application notes are general engineering guidance. Verify the property class and any approval requirement against your own design calculation.

What Are Equal-End Stud Bolt Used For? application image

The primary duty of Equal-End Stud Bolts is clamping a joint from both ends where a headed bolt cannot be used, tightened by the nuts rather than by the fastener itself. Below: the sectors that specify them in volume, the checklist used to select the right size and material for the application, installation notes, and the known limits of the type. Stocked across roughly M6 to M36, they cover general to heavy-duty work.

Typical Applications for Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093)

The most common settings where these are specified:

  • Automotive & transport: chassis, suspension and powertrain mounting points subject to vibration.
  • Heavy machinery: securing gearboxes, frames and guarding on plant that sees shock loads.
  • Energy & infrastructure: tower, pylon and pipework supports exposed to weather and long service life.
  • General machine building: fastening covers, brackets, motors and sub-assemblies on production equipment.
  • Maintenance & repair (MRO): a stocked size for servicing existing plant where the original fastener spec must be matched.

How to Specify Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093) for Your Application

  • Size: Match the nominal size to the mating thread or hole. This product spans M6–M36; check the full table below for the exact dimensions of each size.
  • Strength class: Choose the property class (e.g. 8.8, 10.9, 12.9 or A2/A4 stainless) for the load and environment, and tighten to the matching torque so the joint relies on preload, not friction.
  • Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
  • Standard: This product is supplied to GB/T 901 / DIN 939. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.

Installation & Assembly Practice

  • Tighten to the torque for the size and property class with a calibrated wrench — the joint is held by preload, not by the thread friction alone.
  • Ensure at least one full thread projects beyond the nut after tightening, and never re-use a bolt that has been tightened into yield.
  • Under slotted or oversized holes, fit a hardened washer so the preload does not relax into the hole edge.

Common Selection Mistakes with Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093)

  • Specifying class 12.9 "to be safe" in a corrosive environment — high classes are more sensitive to hydrogen embrittlement and stress corrosion; 8.8 hot-dip galvanized often outlasts them outdoors.
  • Choosing a length that puts the shear plane through the threaded portion when a plain shank (partially threaded bolt) was available.
  • Mixing stainless bolts with plated-steel nuts: the joint loses its corrosion logic and can gall or seize.

Where Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093) Are Not the Right Choice

Not for permanent joints that will never be opened (a rivet or weld is cheaper), and not where the head must sit flush — use a countersunk screw instead.

Technical Drawing

Customize the parameters below — every spec field is editable, and the drawing redraws to match the values you choose. Changing the size will snap the other fields to that size's standard values; you can then override any individual value.

Sends the selected values to the quote form below.

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The form below follows the current technical drawing configuration. Change the drawing values above and the request details update automatically.

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Specification
Business Information

Dimensions & Specifications (GB/T 901 / DIN 939)

Thread sizePitch (mm)Length L (mm)Engagement depth bm (mm)MaterialReference standard
M61.0508Cl. 8.8 alloy steelDIN 939 / GB/T 901
M81.256010Cl. 8.8 alloy steelDIN 939 / GB/T 901
M101.58015Cl. 8.8 alloy steelDIN 939 / GB/T 901
M121.7510018Cl. 8.8 alloy steelDIN 939 / GB/T 901
M142.012021Cl. 8.8 alloy steelDIN 939 / GB/T 901
M162.015024Cl. 8.8 alloy steelDIN 939 / GB/T 901
M202.518030Cl. 8.8 alloy steelDIN 939 / GB/T 901
M243.020036Cl. 8.8 alloy steelDIN 939 / GB/T 901
M303.524045Cl. 8.8 alloy steelDIN 939 / GB/T 901
M364.028054Cl. 8.8 alloy steelDIN 939 / GB/T 901
Inside the plant

Manufactured in our own plant

This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided.

  1. Wire rod feeding into a cold heading machine
    01

    Cold heading

    Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail.

    Head dimensions and under-head radius checked at set-up and per shift.

  2. Thread rolling machine producing bolt threads
    02

    Thread rolling

    Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch.

    Go / no-go ring gauges to ISO 965 tolerance class 6g.

  3. Baskets of bolts staged for heat treatment
    03

    Heat treatment

    Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it.

    Core hardness and tensile tested per lot to ISO 898-1.

  4. Zinc plated bolts in a treatment basket
    04

    Surface treatment

    Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list.

    Coating thickness and neutral salt spray hours to ISO 9227.

Frequently Asked Questions

How tight should Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093) be torqued?

Tighten to the torque for the size and property class so the joint is held by bolt preload. The size pages and torque reference table give recommended values; use a calibrated torque wrench for anything structural.

What material should Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093) be for outdoor use?

For damp, coastal or chemical environments specify A4 (316) stainless or a suitably coated steel. For indoor or dry use, A2 (304) stainless or zinc-plated steel is normally adequate.

Are Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093) made to a recognized standard?

Yes — they are manufactured to GB/T 901 / DIN 939, so dimensions are interchangeable between suppliers when you quote the standard on your order.

What are Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093) used for?

Clamping a joint from both ends where a headed bolt cannot be used, tightened by the nuts rather than by the fastener itself. They are supplied to GB/T 901 / DIN 939.

Can I get a quote for Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093) in the size and material I need?

Yes. Use the technical drawing and quote form on this page to set the size and options, then send the exact configuration to our team for pricing and lead time.