--- title: "What Are Studs & Threaded Rods Used For?" description: "Studs & Threaded Rods (DIN 939 / DIN 975) are used for clamping a joint from both ends where a headed bolt cannot be used, tightened by the nuts rather than…" url: https://engineeringhardware.com/applications/studs-threaded-rods/ source: Engineering Hardware & Fasteners --- # What Are Studs & Threaded Rods Used For? Bolts · DIN 939 / DIN 975 · Application guide Typical applications, the industries that specify studs & threaded rods, and how to choose the right size, material and finish for the joint. Studs & Threaded Rods 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 DIN 939 / DIN 975, 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:** DIN 939 / DIN 975 - **Thread size range:** M4 to M48 - **Category:** Bolts Application notes are general engineering guidance. Verify the property class and any approval requirement against your own design calculation. ![What Are Studs & Threaded Rods Used For? application image](https://engineeringhardware.com/wp-content/uploads/2026/06/Studs-Threaded-Rods-—-DIN-939-／-DIN-975.webp) Application guide for Studs & Threaded Rods to DIN 939 / DIN 975. The core duty of the type is clamping a joint from both ends where a headed bolt cannot be used, tightened by the nuts rather than by the fastener itself. The typical industries, the how-to-specify checklist, assembly practice and the exclusion cases are set out below. Stocked across roughly M4 to M48, they cover general to heavy-duty work. ## Typical Applications for Studs & Threaded Rods The most common settings where these are specified: - **Fabrication & metalwork:** bench and on-site assembly of steel frames, enclosures and weldments. - **Structural steel:** bolting beams, base plates and bracing where a defined preload and property class are required. - **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. ## How to Specify Studs & Threaded Rods for Your Application - **Size:** Match the nominal size to the mating thread or hole. This product spans M4–M48; 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 DIN 939 / DIN 975. 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 Studs & Threaded Rods - 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 Studs & Threaded Rods 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. Custom manufacturing · Made to drawing ## Need a studs & threaded rods outside the standard range? A non-standard bolt is quoted from the drawing; where one already exists in the catalog, the special is usually a variation on its tooling. Made by cold heading or hot forging. Minimum order from 2,000 pieces; samples within 7 days of drawing approval. [Custom bolt manufacturing](https://engineeringhardware.com/custom/bolts/)[Send a drawing](https://engineeringhardware.com/custom/bolts/#rfq) ## Technical Drawing Dimensioned line drawing of M4 Studs & Threaded Rods to DIN 939 / DIN 975. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected. - **Pitch (mm):** 0.7 - **Point type:** M4 - **Common lengths (mm):** 10~100 - **Notes:** Stud, equal thread both ends ## Dimensions & Specifications (DIN 939 / DIN 975) | Thread size | Pitch (mm) | Point type | Common lengths (mm) | Reference standard | Notes | | --- | --- | --- | --- | --- | --- | | M4 | 0.7 | M4 | 10~100 | DIN 939 | Stud, equal thread both ends | | M5 | 0.8 | M5 | 10~120 | DIN 939 | Stud, equal thread both ends | | M6 | 1.0 | M6 | 12~160 | DIN 939 | Stud, equal thread both ends | | M8 | 1.25 | M8 | 16~200 | DIN 939 | Stud, equal thread both ends | | M10 | 1.5 | M10 | 20~250 | DIN 939 | Stud, equal thread both ends | | M12 | 1.75 | M12 | 25~300 | DIN 939 | Stud, equal thread both ends | | M14 | 2.0 | M14 | 30~300 | DIN 939 | Stud, equal thread both ends | | M16 | 2.0 | M16 | 35~300 | DIN 939 | Stud, equal thread both ends | | M18 | 2.5 | M18 | 40~300 | DIN 939 | Stud, equal thread both ends | | M20 | 2.5 | M20 | 45~300 | DIN 939 | Stud, equal thread both ends | | M22 | 2.5 | M22 | 50~300 | DIN 939 | Stud, equal thread both ends | | M24 | 3.0 | M24 | 50~300 | DIN 939 | Stud, equal thread both ends | | M27 | 3.0 | M27 | 55~300 | DIN 939 | Stud, equal thread both ends | | M30 | 3.5 | M30 | 60~300 | DIN 939 | Stud, equal thread both ends | | M36 | 4.0 | M36 | 70~300 | DIN 939 | Stud, equal thread both ends | | M42 | 4.5 | M42 | 80~300 | DIN 940 | Stud, equal thread both ends | | M48 | 5.0 | M48 | 90~300 | DIN 940 | Stud, equal thread both ends | | M4 | 0.7 | Fully threaded | 1000/2000/3000 | DIN 975 | Fully threaded rod, cut to length | | M5 | 0.8 | Fully threaded | 1000/2000/3000 | DIN 975 | Fully threaded rod, cut to length | | M6 | 1.0 | Fully threaded | 1000/2000/3000 | DIN 975 | Fully threaded rod, cut to length | | M8 | 1.25 | Fully threaded | 1000/2000/3000 | DIN 975 | Fully threaded rod, cut to length | | M10 | 1.5 | Fully threaded | 1000/2000/3000 | DIN 975 | Fully threaded rod, cut to length | | M12 | 1.75 | Fully threaded | 1000/2000/3000 | DIN 975 | Fully threaded rod, cut to length | | M16 | 2.0 | Fully threaded | 1000/2000/3000 | DIN 975 | Fully threaded rod, cut to length | | M20 | 2.5 | Fully threaded | 1000/2000/3000 | DIN 975 | Fully threaded rod, cut to length | | M24 | 3.0 | Fully threaded | 1000/2000/3000 | DIN 975 | Fully threaded rod, cut to length | | M30 | 3.5 | Fully threaded | 1000/2000/3000 | DIN 975 | Fully threaded rod, cut to length | 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](https://engineeringhardware.com/wp-content/uploads/2026/08/09-wire-rod-feed-cold-heading-machine.webp) 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](https://engineeringhardware.com/wp-content/uploads/2026/08/03-thread-rolling-machine-bolt-production.webp) 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](https://engineeringhardware.com/wp-content/uploads/2026/08/05-heat-treatment-baskets-black-bolts.webp) 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](https://engineeringhardware.com/wp-content/uploads/2026/08/23-zinc-plated-bolts-treatment-basket.webp) 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 Studs & Threaded Rods 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 Studs & Threaded Rods 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 Studs & Threaded Rods made to a recognized standard? Yes — they are manufactured to DIN 939 / DIN 975, so dimensions are interchangeable between suppliers when you quote the standard on your order. ### What are Studs & Threaded Rods 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 DIN 939 / DIN 975. ### Can I get a quote for Studs & Threaded Rods 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. ## Related Pages Product page: [Studs & Threaded Rods — specifications & sizes](https://engineeringhardware.com/fastener/studs-threaded-rods/) ### Studs & Threaded Rods Specification Guides ### Related Fastener Applications