Screws · DIN 7981
DIN 7981 Phillips Pan Head Self Tapping Screw
Accurate Fastners manufactures and supplies DIN 7981 Phillips pan head self tapping screws in stainless steel grades SS 304 and SS 316, cold forged to the DIN 7981 standard. Available in ST diameters from M2.9 to M6.3 and lengths from 6.5 mm to 50 mm, these screws are suited to a broad range of light-to-medium assembly applications.
- Standard
- DIN 7981
- Grades
- 304 / 316
- Size
- M2.9 – M6.3 (ST sizes)
- Length
- 6.5 mm – 50 mm
Overview
What is the DIN 7981 Phillips Pan Head Self Tapping Screw?
A DIN 7981 self tapping screw is a threaded fastener designed to form or cut its own mating thread as it is driven into a pre-drilled or punched hole. The DIN 7981 standard specifically defines the pan head form with a Phillips cross recess, governing the dimensional relationships between the head diameter, head height, recess depth, and shank geometry. This allows interchangeable use of standard Phillips drivers across compliant fasteners, making assembly straightforward in production environments.
The pan head profile is characterised by a low, wide, domed top surface with near-vertical sides and a flat bearing face. This geometry distributes the clamping load over a relatively large area compared with a countersunk or hex head, which can be an advantage when fastening into thinner or softer substrates. The Phillips drive recess is engineered to centre the driver bit automatically and to cam out at a defined torque, which may help reduce overdriving in automated and hand assembly alike.
Cold forging is the manufacturing process used for these screws. In cold forging, the fastener is formed from wire rod at ambient temperature under high compressive force, which typically results in a refined grain structure and good dimensional consistency throughout the production run. Accurate Fastners applies quality checks during both procurement and delivery stages to maintain conformance with the DIN 7981 specification across the stated size range.
In Depth
Product description
Construction and Geometry
Each screw comprises three principal elements: the pan head with its Phillips cross recess, the cylindrical shank, and the self tapping thread form. The head height is relatively shallow relative to the head diameter, presenting a rounded upper surface with a flat underside bearing face. Dimensional parameters such as head diameter, recess width, and shank diameter are governed by DIN 7981, ensuring consistency between batches and compatibility with standard tooling.
The self tapping thread has a coarser pitch and a sharper thread angle than a standard machine screw thread. This geometry is intended to displace or cut substrate material during installation to create an engaged thread form without requiring a pre-tapped hole. The thread runs to a gimlet or tapered point at the tip, which assists with entry and alignment. Cold forging produces this thread form with the work-hardening effect that is generally associated with cold-formed fasteners.
Functional Behaviour in an Assembly
When driven into a suitable substrate such as sheet metal, thin plastic, or light-gauge structural sections, the screw tip locates in the pilot hole and the thread progressively engages the hole wall as torque is applied. The material displaced or cut by the thread forms a helical groove that mirrors the screw thread, creating mechanical interlock. Pull-out resistance depends on the number of engaged thread turns, so selecting an appropriate length relative to the substrate thickness is an important assembly consideration.
The pan head bearing face seats against the external surface of the top panel or bracket, clamping it against the underlying substrate. Because the thread is formed in situ, the assembly is generally not intended for frequent disassembly and reassembly, as repeated removal may degrade the formed thread in softer substrates. The Phillips drive allows use of both manual screwdrivers and power drivers, which is convenient in moderate-volume production or field installation scenarios.
How It Differs from Similar Fasteners
DIN 7981 is specifically the Phillips pan head variant within the DIN 798x family of self tapping screws. A related standard, DIN 7982, covers the countersunk (flat) head form, while DIN 7976 covers the hex head. Choosing between head forms depends on whether a flush finish is required, whether a hex driver is preferred, or whether a broad bearing surface is the priority. The pan head is often selected when a neat, low-profile appearance and a wide bearing face are both desired.
Self tapping screws also differ from self-drilling screws (TEK screws): a self tapping screw requires a pilot hole of a specified diameter, whereas a self-drilling screw incorporates a drill tip that can penetrate the substrate without pre-drilling. DIN 7981 is a self tapping type and therefore assumes a pilot hole is provided. It should not be confused with thread-forming screws for plastics, which displace rather than cut material and carry a different thread geometry designed for polymeric substrates.
Material & Grade
Material and grade information
- SS 304
- SS 316
These screws are available in SS 304, an austenitic stainless steel containing nominally 18% chromium and 8% nickel. SS 304 offers good general corrosion resistance in many indoor and mildly exposed environments and is commonly used across food processing equipment, pharmaceutical machinery, water treatment components, and general light fabrication. Its combination of workability and corrosion performance makes it one of the most widely specified grades for stainless fasteners in non-aggressive service conditions.
SS 316 includes an addition of molybdenum, typically around 2–3%, which generally enhances resistance to chloride-containing environments and certain chemical media compared with SS 304. It is often selected when assemblies may be exposed to humid, saline, or chemically active conditions. For applications such as RO water purifier components or equipment used near coastal environments, SS 316 may be the more appropriate grade. The specific grade required should be confirmed with the Accurate Fastners sales team based on the intended service environment.
Grades shown are those documented for this product in the Accurate Fastners brochure. General material notes are guidance only; confirm grade selection for your environment.
Technical Data
Technical specifications
| Product type | Screw – DIN 7981 Phillips Pan Head Self Tapping Screw |
|---|---|
| Material | Stainless steel |
| Material grade | SS 304, SS 316 |
| Applicable standard | DIN 7981 |
| Nominal diameter / size | M2.9 – M6.3 (ST sizes) |
| Length | 6.5 mm – 50 mm |
| Thread type | Self-tapping thread |
| Head / form | Pan head |
| Drive / tightening | Phillips cross recess |
| Manufacturing process | Cold forged |
Sizes
Available sizes
Documented size range
M2.9 – M6.3 (ST sizes)
Documented length range
6.5 mm – 50 mm
Individual sizes within the documented range, thread pitches and lengths are confirmed at quotation stage.
Applications
Industrial applications
Water Treatment Equipment
SS 316 variants of these screws may be used to fasten enclosures, brackets, and panel sub-assemblies in RO water purifier units, where moisture exposure makes stainless steel a practical material choice.
Solar Energy Mounting Structures
Lightweight mounting brackets, junction box covers, and sheet metal sub-frames in solar energy installations may use DIN 7981 pan head screws where a self tapping fastener is suitable for thin-gauge sections.
LED Lighting Assemblies
LED luminaire housings and driver enclosures often use thin aluminium or galvanised steel sheet, where the self tapping thread form can create a reliable joint without a separate tapping operation.
Pharmaceutical Machinery Panels
Equipment enclosures in pharmaceutical environments may specify SS 304 or SS 316 fasteners. The pan head profile offers a broad bearing face on sheet panels and is compatible with Phillips driver tooling in assembly lines.
Food and Beverage Equipment
Sheet metal guards, access panels, and splash covers on food processing machinery may use stainless self tapping screws, where hygiene requirements and cleanability are relevant selection considerations.
Featured for: RO Water Purifier, LED Lighting
Features & Selection
Features and selection considerations
Design features
DIN 7981 Compliant Dimensions
Head diameter, head height, shank diameter, and Phillips recess geometry conform to DIN 7981, ensuring compatibility with standard tooling and consistent assembly behaviour across batches.
Cold Forged Construction
Cold forging produces a refined grain structure and good dimensional uniformity, which are generally associated with consistent mechanical performance in finished cold-formed fasteners.
Phillips Cross Recess Drive
The Phillips recess centres standard driver bits automatically and is compatible with both manual screwdrivers and power tools, supporting a range of assembly methods.
Wide Pan Head Bearing Face
The low-profile pan head distributes clamp load across a broad area, which may reduce the risk of pull-through in thinner or softer substrate materials compared with narrower head forms.
Self Tapping Thread Form
The coarse, sharp thread creates its own mating thread in a pre-drilled pilot hole, eliminating the need for a separate tapping operation and simplifying assembly in sheet metal or similar substrates.
Before you order
Pilot Hole Diameter
DIN 7981 self tapping screws require a correctly sized pilot hole. The recommended pilot hole diameter varies with screw size and substrate material; consult the DIN 7981 specification or supplier guidance before specifying.
Length and Thread Engagement
Select a length within the 6.5–50 mm range that provides sufficient thread engagement in the substrate for the required pull-out resistance, accounting for any panel thickness between the head and the tapping substrate.
Grade Selection by Environment
SS 304 is suitable for many general indoor or mildly exposed environments. SS 316 may be preferable where chloride exposure or chemical media are anticipated. Discuss the service environment with the Accurate Fastners team.
Quantity and Documentation
For volume orders, confirm quantity, size, grade, and any documentation requirements such as material test reports at the enquiry stage. Accurate Fastners quality checks are performed during procurement and delivery.
FAQs
Frequently asked questions
What substrates are DIN 7981 self tapping screws typically used with?
DIN 7981 self tapping screws are commonly used with sheet metal, light-gauge structural sections, and certain rigid plastics. A correctly sized pilot hole must be provided. Suitability depends on substrate material, thickness, and the specific assembly requirements.
Which stainless steel grades are available for these screws?
Accurate Fastners offers DIN 7981 Phillips pan head self tapping screws in SS 304 and SS 316. The choice between grades typically depends on the corrosion resistance required in the intended service environment. Contact the sales team for grade-specific guidance.
What size range is available?
Screws are available in ST diameters from M2.9 to M6.3 and lengths from 6.5 mm to 50 mm. If a specific combination of diameter and length is needed, raise it at the enquiry stage to confirm availability from the current range.
What does the DIN 7981 standard govern?
DIN 7981 is a German institute standard that specifies the dimensional requirements for cross-recessed pan head tapping screws, covering head form, recess geometry, thread parameters, and shank proportions to ensure consistent, interchangeable manufacture.
Are complementary fasteners such as washers available from Accurate Fastners?
Yes. Accurate Fastners supplies a range of complementary products including washers, nuts, bolts, and other screws. If your project requires matching stainless steel washers or related fasteners, these can be discussed as part of the same enquiry.
How can I request a quotation for these screws?
You may submit an enquiry through the website enquiry form, email the team at export@accuratefastners.com, or contact via WhatsApp. Please include the required diameter, length, grade, and quantity so the team can respond with an accurate quotation.
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- DIN 912304 · 316 · 202
DIN 912 Socket Head Cap Screw (Allen Cap Screw)
Size: M3 – M16
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