The DIN 7984 stainless low head screw is a metric socket fastener for machinery and equipment where vertical head clearance is limited. DIN 7984:2022-03 is the current German standard and covers hexagon socket head cap screws with low head and reduced loadability from M3 to M24, product grade A, in steel and stainless steel. Unlike DIN 912 / ISO 4762 screws, the reduced cylindrical head is shorter and uses a smaller internal hex drive. Common stainless market configurations include A2 and A4 grades, with mechanical properties referenced to ISO 3506-1.
Product Overview and Key Features
DIN 7984 keeps the cylindrical socket-head concept while reducing head height for compact assemblies. The lower head also means reduced loadability, so full-height socket cap screw load or tightening assumptions should not be transferred automatically.
- Low cylindrical head: reduces vertical clearance compared with a conventional DIN 912 / ISO 4762 socket head cap screw.
- Internal hex drive: allows installation from above with standard hex-key tooling.
- Metric coarse threads: the standard covers M3 through M24.
- Reduced loadability: head geometry limits the load that can be transferred through the screw compared with full-height designs.
- Stainless options: A2 and A4 are common choices for corrosion-resistant machinery and equipment.
DIN 7984 Stainless Low Head Screw Specifications
Specification Overview
| Item | Specification / Common Configuration |
|---|---|
| Current standard | DIN 7984:2022-03 |
| Product form | Hexagon socket head cap screw with low head and reduced loadability |
| Product grade | A |
| Thread range | M3 to M24 |
| Thread form | ISO metric coarse thread |
| Common stainless grades | A2 and A4 |
| Mechanical-property reference | ISO 3506-1:2020 for corrosion-resistant stainless fasteners |
| Common market property class | A2-70 and A4-70, subject to reduced-head loadability requirements |
| Common surface condition | Natural stainless or passivated |
Dimensions and Thread Details
The table shows selected DIN 7984 dimensions and representative A2 stainless commercial lengths. P is coarse pitch, dk maximum head diameter, k maximum head height, s nominal hex-key size, and b minimum thread length for screw lengths up to 125 mm. Dimensions are millimetres.
| Thread | P (mm) | Catalog Length Examples (mm) | dk Max (mm) | k Max (mm) | s (mm) | b Min. (mm) |
|---|---|---|---|---|---|---|
| M3 | 0.50 | 6, 8, 12, 20, 30 | 5.5 | 2.0 | 2.0 | 12 |
| M4 | 0.70 | 6, 10, 20, 30, 40 | 7.0 | 2.8 | 2.5 | 14 |
| M5 | 0.80 | 6, 10, 20, 50, 60 | 8.5 | 3.5 | 3.0 | 16 |
| M6 | 1.00 | 6, 20, 40, 60, 80 | 10.0 | 4.0 | 4.0 | 18 |
| M8 | 1.25 | 8, 22, 45, 60, 80 | 13.0 | 5.0 | 5.0 | 22 |
| M10 | 1.50 | 14, 30, 40, 55 | 16.0 | 6.0 | 7.0 | 26 |
| M12 | 1.75 | 16, 30, 50, 80, 100 | 18.0 | 7.0 | 8.0 | 30 |
| M16 | 2.00 | 20, 30, 50, 80, 120 | 24.0 | 9.0 | 12.0 | 38 |
DIN 7984 also includes M14, M18, M20, M22, and M24. Longer screws use larger specified minimum thread lengths, while shorter commercial screws may be fully threaded. Do not assume every diameter and length combination is available or that a fully threaded short screw establishes the configuration for all lengths.
Common Stainless Grades and Surface Finishes
A2 Stainless Steel
A2 is a common general-purpose austenitic stainless option for indoor, humid, and moderately corrosive industrial environments. A2-70 is widely cataloged for DIN 7984 screws. Exact chemistry should be stated separately when a drawing specifically requires 304 or another material designation.
A4 Stainless Steel
A4 contains molybdenum and is commonly selected for greater resistance to chloride-related pitting. It is often considered for outdoor, marine-adjacent, food-processing, or chemical environments where the application calls for higher corrosion resistance than a general A2 configuration.
Surface Condition and Galling
Natural stainless and passivated finishes are common. Zinc plating is not normally required for stainless steel. Stainless-on-stainless threads can gall, so lubricant, tightening speed, thread fit, and the approved tightening procedure should be considered for repeated or high-preload assembly.
Typical Applications and Selection Considerations
- Compact machinery, automation equipment, fixtures, tooling, and motor assemblies.
- Electrical cabinets, control equipment, covers, brackets, and housings with restricted head clearance.
- Food, packaging, laboratory, and processing equipment using corrosion-resistant fastening.
- OEM products where a standard socket head is too tall but a countersunk seat is undesirable.
Flybear’s socket head versus button head versus countersunk screw guide explains head-clearance tradeoffs. Buyers can also compare the DIN 912 304 stainless socket head cap screw when greater head height and loadability are acceptable.
Ordering and Quality Documentation
An RFQ should state DIN 7984:2022-03, thread size, nominal length, A2 or A4 grade, required property class, surface condition, quantity, thread length requirement, and mating component. Buyers may request material verification, dimensional inspection, thread gauging, mechanical testing where applicable, socket inspection, and passivation documentation. Flybear’s quality control and inspection page describes available support; exact acceptance criteria should be agreed for the order.
Frequently Asked Questions
Is DIN 7984 still a current standard?
Yes. DIN 7984:2022-03 is the current German standard for hexagon socket head cap screws with low head and reduced loadability. It replaced the corrected 2021 edition and covers M3 through M24.
Is DIN 7984 the same as ISO 14580?
No. DIN 7984 uses a hexagon socket drive. ISO 14580 covers low-head screws with a hexalobular internal drive and a different size range. They should not be treated as equivalent standards simply because both use a reduced-height head.
How does DIN 7984 differ from DIN 912?
DIN 7984 has a substantially lower cylindrical head and a smaller internal hex drive. This saves vertical space but reduces head loadability. DIN 912 / ISO 4762 is generally the better starting point when full-height head clearance and greater head loadability are available.
Should I choose A2 or A4 stainless?
A2 suits many general industrial environments. A4 is commonly selected when chloride exposure or more aggressive corrosion conditions justify molybdenum-bearing stainless. Final selection should consider the actual environment, temperature, mating material, and cleaning process.
What information should I provide for quotation?
Provide the DIN 7984 size, length, stainless grade, property class, surface condition, quantity, required thread length, mating material, and application. Include a controlled drawing when head clearance, special length, or mechanical acceptance requirements are critical.
Request a Quote for DIN 7984 Stainless Low Head Screws
Send Flybear Industrial your DIN 7984 stainless low head screw size, length, A2 or A4 grade, required property class, surface condition, quantity, and application details. Include drawings for controlled low-clearance assemblies or special configurations. Submit the requirements through the Flybear fastener RFQ page for technical review and quotation.
