DIN912 Hexagon Socket Head Cap Screws
DIN 912 Hexagon Socket Head Cap Screws combine a cylindrical cap head with an internal hexagon socket to provide a compact and efficient fastening design. The cylindrical head gives the screw a neat, low-projection profile, while the recessed socket allows tightening torque to be applied directly through the center of the head. This construction provides a secure connection without requiring the clearance around the fastener that is normally needed for an external hexagon head.
The standardized geometry of DIN 912 makes these socket head cap screws suitable for repeatable mechanical assembly and replacement. Their head diameter, head height, socket drive, and threaded shank are designed as an integrated fastening system, allowing engineers to select the appropriate screw according to joint dimensions, available space, required clamping performance, and material. Depending on the specification, DIN 912 screws are available in carbon or alloy steel and stainless steel grades for applications ranging from precision components and tooling to industrial machinery and equipment assemblies.
Specification:
DIN 912 Hexagon Socket Head Cap Screws are manufactured to a standardized socket head design, with the dimensional relationship between the threaded shank, cylindrical head, and internal hexagon recess controlled for consistent assembly. The specification covers the basic geometry of the screw as well as the requirements that determine its mechanical performance and compatibility with the mating component.
Depending on the required load and service environment, DIN 912 screws can be supplied in carbon or alloy steel with property classes such as 8.8, 10.9, and 12.9, as well as stainless steel grades including A2-70 and A4-70. Metric coarse threads are commonly supplied, while thread size and screw length are selected according to the joint design. Steel versions can be supplied with finishes such as zinc plating, black oxide, or other protective coatings, while stainless steel versions are generally supplied in their natural or specified surface condition.
| Item | Specification |
|---|---|
| Standard | DIN912 |
| Product Type | Hexagon Socket Head Cap Screw |
| Head Type | Cylindrilcal Head |
| Drive | Internal Hexagon Socket |
| Thread | Metric Coarse |
| Thread Diameter | M1.4-M100 |
| Proerty Class | 8.8,10.9,12.9 A2-70,A4-70 |
| Material | Carbon Steel,Alloy Steel,Stainless Steel |
| Surface Treatment | Bright Finish |
Dimension Chart of DIN912 Hexagon Socket Head Cap Screws:
The DIN 912 dimension chart provides the dimensional references needed to select a socket head cap screw for a specific joint. The nominal diameter and screw length determine the threaded engagement, while the cylindrical head dimensions define the space occupied above the assembled component. The internal hexagon size should also be considered when selecting the correct Allen key or hex bit and when checking tool access around the fastening location.
The chart covers the principal dimensions of DIN 912 screws, including nominal thread diameter (d), screw length (l), head diameter (dk), head height (k), and socket size (s). These dimensions allow engineers to check thread engagement, head clearance, tool compatibility, and available installation space before specifying the screw. For assemblies with closely positioned components, comparing the head diameter and socket dimensions with the surrounding geometry can help avoid interference during installation or maintenance.
| Mon | M1.4 | M1.6 | M2 | M2.5 | M3 | M4 | M5 | M6 | M8 | M10 | M12 | M14 | M16 | M18 | M20 |
| P | 0.3 | 0.35 | 0.4 | 0.45 | 0.5 | 0.7 | 0.8 | 1 | 1|1.25 | 1|1.25|1.5 | 1.25|1.5|1.75 | 1.5|2 | 1.5|2 | 1.5|2|2.5 | 1.5|2|2.5 |
| dk max | 2.6 | 3 | 3.8 | 4.5 | 5.5 | 7 | 8.5 | 10 | 13 | 16 | 18 | 21 | 24 | 27 | 30 |
| dk min | 2.46 | 2.86 | 3.62 | 4.32 | 5.32 | 6.78 | 8.28 | 9.78 | 12.73 | 15.73 | 17.73 | 20.67 | 23.67 | 26.67 | 29.67 |
| da max | 1.8 | 2 | 2.6 | 3.1 | 3.6 | 4.7 | 5.7 | 6.8 | 9.2 | 11.2 | 13.7 | 15.7 | 17.7 | 20.2 | 22.4 |
| e min | 1.5 | 1.73 | 1.73 | 2.3 | 2.87 | 3.44 | 4.58 | 5.72 | 6.86 | 9.15 | 11.43 | 13.72 | 16 | 16 | 19.44 |
| k max | 1.4 | 1.6 | 2.0 | 2.5 | 3.0 | 4.0 | 5.0 | 6.0 | 8.0 | 10 | 12 | 14 | 16 | 18 | 20 |
| k min | 1.26 | 1.46 | 1.86 | 2.36 | 2.86 | 3.82 | 4.82 | 5.70 | 7.64 | 9.64 | 11.57 | 13.57 | 15.57 | 17.57 | 19.48 |
| r min | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.2 | 0.2 | 0.25 | 0.4 | 0.4 | 0.6 | 0.6 | 0.6 | 0.6 | 0.8 |
| s min | 1.32 | 1.52 | 1.52 | 2.02 | 2.52 | 3.02 | 4.02 | 5.02 | 6.02 | 8.025 | 10.025 | 12.032 | 14.032 | 14.032 | 17.05 |
| s max | 1.36 | 1.56 | 1.56 | 2.06 | 2.58 | 3.08 | 4.095 | 5.14 | 6.14 | 8.175 | 10.175 | 12.212 | 14.212 | 14.212 | 17.23 |
| t min | 0.6 | 0.7 | 1 | 1.1 | 1.3 | 2 | 2.5 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Mon | M20 | M22 | M24 | M27 | M30 | M33 | M36 | M42 | M48 | M56 | M64 | M72 | M80 | M90 | M100 |
| P | 1.5|2|2.5 | 1.5|2|2.5 | 2|3 | 2|3 | 2|3.5 | 2|3.5 | 3|4 | 3|4.5 | 3|5 | 4|5.5 | 4|6 | 4|6 | 4|6 | 4|6 | 4|6 |
| dk max | 30 | 33 | 36 | 40 | 45 | 50 | 54 | 63 | 72 | 84 | 96 | 108 | 120 | 135 | 150 |
| dk min | 29.67 | 32.61 | 35.61 | 39.61 | 44.61 | 49.61 | 53.54 | 62.54 | 71.54 | 83.46 | 95.46 | 107.46 | 119.46 | 134.37 | 149.37 |
| da max | 22.4 | 24.4 | 26.4 | 30.4 | 33.4 | 36.4 | 39.4 | 45.5 | 52.6 | 63 | 71 | 79 | 87 | 97 | 107 |
| e min | 19.44 | 19.44 | 21.73 | 21.73 | 25.15 | 27.43 | 30.85 | 36.57 | 41.13 | 46.83 | 52.53 | 62.81 | 74.21 | 85.61 | 97.04 |
| k max | 20 | 22 | 24 | 27 | 30 | 33 | 36 | 42 | 48 | 56 | 64 | 72 | 80 | 90 | 100 |
| k min | 19.48 | 21.48 | 23.48 | 26.48 | 29.48 | 32.38 | 35.38 | 41.38 | 47.38 | 55.38 | 63.26 | 71.26 | 79.26 | 89.13 | 99.13 |
| r min | 0.8 | 0.8 | 0.8 | 1.0 | 1.0 | 1.0 | 1.0 | 1.2 | 1.6 | 2.0 | 2 | 2 | 2 | 2.5 | 2.5 |
| s min | 17.05 | 17.05 | 19.065 | 19.065 | 22.065 | 24.065 | 27.065 | 32.08 | 36.08 | 41.08 | 46.08 | 55.1 | 65.1 | 75.1 | 85.12 |
| s max | 17.23 | 17.23 | 19.275 | 19.275 | 22.275 | 24.275 | 27.275 | 32.33 | 36.33 | 41.33 | 46.33 | 55.4 | 65.4 | 75.4 | 85.47 |
| t min | 10 | 11 | 12 | 13.5 | 15.5 | 18 | 19 | 24 | 28 | 34 | 38 | 43 | 48 | 54 | 60 |
Application of DIN912 Hexagon Socket Head Cap Screws:
DIN 912 Hexagon Socket Head Cap Screws are used across mechanical assemblies where the combination of a compact cylindrical head and internal hexagon drive fits the design of the joint. Smaller sizes such as M2–M4 are commonly suitable for precision components, sensor mounts, camera and optical equipment, small actuators, and electronic mechanisms. M5–M8 sizes provide a practical range for machine tooling, automation equipment, linear guides, clamping fixtures, and general industrial machinery, while larger sizes can be selected for heavier equipment frames, die sets, mechanical supports, and high-load structural components when the joint design requires a socket head screw.
The property class is normally selected according to the mechanical load rather than simply the screw size. 8.8 screws can be used for general machinery, equipment guards, brackets, and assembly fixtures, while 10.9 and 12.9 grades are better suited to highly loaded connections such as machine-tool fixtures, mold components, actuator assemblies, clamping systems, and precision machinery where higher tensile and preload capability is required. The higher-strength grades are particularly useful when a compact screw head is preferred but the joint still requires substantial clamping force.
Material selection also changes the appropriate application. A2-70 stainless steel DIN 912 screws are suitable for equipment exposed to humidity or occasional outdoor conditions, including packaging machinery, commercial equipment, instrumentation, and stainless steel assemblies. A4-70 stainless steel is better suited to more demanding environments such as marine equipment, chemical-processing machinery, coastal installations, and food-processing systems where improved corrosion resistance is important. Carbon and alloy steel versions are generally preferred for heavily loaded mechanical components where mechanical strength is the primary consideration.
The socket head configuration is especially useful on equipment with closely spaced components or limited clearance around the fastener head. This makes DIN 912 a common choice for removable machine covers, tooling plates, linear-motion assemblies, robotic mechanisms, fixture plates, mold bases, and adjustable mechanical components where a conventional external hexagon bolt would require more surrounding tool clearance. The final size, property class, and material should be selected together with the joint thickness, load, operating environment, and available installation space.