DIN 939 Stud Bolts
DIN 939 Stud Bolts are double-ended threaded fasteners featuring a reduced shank between the two threaded sections. One threaded end is designed to be screwed into a tapped hole or threaded component, while the opposite end extends outward for fastening with a nut. This configuration provides a secure connection while allowing the mating component to be installed and removed without repeatedly threading the stud into the base material.
Manufactured according to the dimensional requirements of DIN 939, our stud bolts are available in carbon steel, alloy steel, and stainless steel for machinery, equipment, flange, piping, and other industrial applications. The reduced shank design helps provide clearance between the threaded sections and can facilitate assembly in applications where conventional fully threaded studs are not suitable. We can supply standard and custom lengths, thread configurations, materials, mechanical grades, and surface finishes according to customer drawings and application requirements.
Specification:
DIN 939 Stud Bolts are manufactured according to the dimensional requirements of DIN 939 and are designed with a reduced shank and a threaded section at both ends. They are commonly used where a stud bolt needs to be installed into a tapped hole while the opposite threaded end is secured with a nut. The standard defines the main dimensional characteristics of the stud bolts, while thread specifications, materials, mechanical properties, and surface finishes can be selected according to the required application.
| Item | Specification |
|---|---|
| Standard | DIN939 |
| Product Type | Stud Bolts |
| System | Metric |
| Size Range | M4-M52 |
| Material | Carbon Steel,Alloy Steel,Stainless Steel |
| Mechanical Property | ISO 898-1,ISO 3506-1 |
| Steel Class | Class4.8,8.8,10.9,12.9 |
| Stainless Steel Class | A2-70,A2-80,A4-70,A4-80 |
| Thread | Metric Coarse |
| Thread Standard | ISO 68-1,ISO 965 |
| Surface Treatment | Black Oxidation,Zinc Plated,Hot Dip Galvanized, Bright Finish,Passivation |
| Inspection | Dimensions, Thread,Mechanical Property,Coating |
Dimension Chart of DIN 939 Stud Bolts:
| Mon | M4 | M5 | M6 | M7 | M8 | M10 | M12 | M14 | M16 | M18 | M20 | M22 | M24 | M27 | M30 | M33 | M36 | M39 | M42 | M45 | M48 | M52 |
| P | 0.7 | 0.8 | 1 | 1 | 1|1.25 | 1.25|1.5 | 1.25|1.5|1.75 | 1.5|2 | 1.5|2 | 1.5|2.5 | 1.5|2.5 | 1.5|2.5 | 2|3 | 2|3 | 2|3.5 | 2|3.5 | 3|4 | 3|4 | 3|4.5 | 3|4.5 | 3|5 | 3|5 |
| b1 | 5 | 6.5 | 7.5 | 9 | 10 | 12 | 15 | 18 | 20 | 22 | 25 | 28 | 30 | 35 | 38 | 42 | 45 | 50 | 52 | 58 | 60 | 65 |
| ds max | 4 | 5 | 6 | 7 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 22 | 24 | 27 | 30 | 33 | 36 | 39 | 42 | 45 | 48 | 52 |
Mechanical Property of DIN 939 Stud Bolts:
Carbon & Alloy Steel DIN939 Stud Bolts — ISO898-1
| Mechanical or physical property | Property class | ||||||||
| 4.6 | 4.8 | 5.6 | 6.8 | 8.8 (d≤16mm) | 8.8(d＞16mm) | 10.9 | 12.9 | ||
| Tensile strength, Rm, MPa | nom. | 400 | 400 | 500 | 600 | 800 | 800 | 1000 | 1200 |
| min. | 400 | 420 | 500 | 600 | 800 | 830 | 1040 | 1220 | |
| Lower yield strength, ReL d, MPa | nom. | 240 | - | 300 | - | - | - | - | - |
| min. | 240 | - | 300 | - | - | - | - | - | |
| Stress at 0,2 % nonproportional elongation, R p0,2, MPa | nom. | - | - | - | - | 640 | 640 | 900 | 1080 |
| min. | - | - | - | - | 640 | 660 | 940 | 1100 | |
| Percentage elongation after fracture for machined test pieces, A, % | min. | 22 | - | 20 | - | 12 | 12 | 10 | 8 |
| Percentage reduction of area after fracture for machined test pieces, Z, % | min. | - | 52 | 48 | 44 | ||||
| Vickers hardness, HV F W 98 N | min. | 120 | 130 | 155 | 190 | 250 | 255 | 320 | 385 |
| max. | 220 | 320 | 335 | 380 | 435 | ||||
| Rockwell hardness, HRC | min. | - | - | - | - | 22 | 23 | 32 | 39 |
| max. | - | - | - | - | 32 | 34 | 39 | 44 | |
Stainless Steel DIN939 Stud Bolts — ISO 3506-1
| Stainless Steel Grade | Property Class | Tension Strength(min)MPA | Stress at 0.2% non-proprotional elongation(min)MPA | Elongation after fracture(min)mm |
| Austenitic | A2-50 | 500 | 210 | 0.6d |
| A2-70 | 700 | 450 | 0.4d | |
| A2-80 | 800 | 600 | 0.3d | |
| A4-50 | 500 | 210 | 0.6d | |
| A4-70 | 700 | 450 | 0.4d | |
| A4-80 | 800 | 600 | 0.3d | |
| Duplex | D6-70 | 700 | 450 | 0.4d |
| D6-80 | 800 | 600 | 0.3d |
Application of DIN 939 Stud Bolts:
DIN 939 Stud Bolts are used where components need to be securely fastened while allowing convenient assembly and disassembly from the nut side. Their double-ended threaded design allows one end to be installed into a tapped hole, while the opposite end remains accessible for a nut and washer. The reduced shank provides clearance between the two threaded sections, making DIN 939 stud bolts particularly suitable for flanged connections, machinery, equipment housings, and assemblies that require repeated maintenance or component replacement.
Flange & Piping Connections
DIN 939 stud bolts are commonly used for flange connections in piping systems, including pumps, valves, pipe fittings, pressure equipment, and industrial process lines. One end of the stud can be installed into a threaded component, while the exposed end is secured with a nut to clamp the mating parts together. This configuration allows the nut and component to be removed without repeatedly installing and removing the stud from the base component. Carbon steel and alloy steel grades can be selected for applications requiring higher mechanical strength, while stainless steel options are suitable for corrosive service environments.
Machinery & Industrial Equipment
The stud bolts are also suitable for machinery, equipment housings, engine components, compressors, pumps, gearboxes, and industrial assemblies where components are frequently removed for inspection, servicing, or replacement. The reduced shank design provides clearance around the central section of the stud and separates the threaded portions, which can be useful where a specific assembly geometry is required. Custom thread lengths, overall lengths, materials, and mechanical grades can be supplied for equipment manufacturers and maintenance applications.
Stainless Steel & Corrosive Environments
For applications exposed to moisture, chemicals, outdoor conditions, or corrosive media, DIN 939 stud bolts can be manufactured from SS304 or SS316 stainless steel. SS304 is suitable for general industrial, food processing, architectural, and outdoor equipment applications, while SS316 provides enhanced corrosion resistance for marine, coastal, chemical processing, wastewater, and chloride-containing environments. Stainless steel stud bolts can be supplied with suitable surface conditions and customized dimensions according to the application requirements.