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Screws · DIN 7984 · Application guide

What Are Low Head Socket Cap Screws Used For?

Typical applications, the industries that specify low head socket cap screws, and how to choose the right size, material and finish for the joint.

Low Head Socket Cap Screws are used for a hexagon socket head cap screw with a low head for limited height. They are manufactured to DIN 7984, 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
A hexagon socket head cap screw with a low head for limited height
Governing standard
DIN 7984
Thread size range
M3 to M24
Category
Screws

Application notes are general engineering guidance. Verify the property class and any approval requirement against your own design calculation.

What Are Low Head Socket Cap Screws Used For? application image

Low Head Socket Cap Screws are selected when an assembly calls for a hexagon socket head cap screw with a low head for limited height. This application guide to the DIN 7984 type covers concrete end-uses, the specification checklist, correct installation, and where an alternative fastener performs better. Stocked across roughly M3 to M24, they cover general to heavy-duty work.

Typical Applications for Low Head Socket Cap Screws

The most common settings where these are specified:

  • Tooling: die sets with shallow counterbores.
  • Automation: compact slides and grippers.
  • Linear motion: rails and carriages.
  • Machine building: covers with limited clearance.

How to Specify Low Head Socket Cap Screws for Your Application

  • Size: Match the nominal size to the mating thread or hole. This product spans M3–M24; check the full table below for the exact dimensions of each size.
  • Drive & head: Pick the drive (socket, cross, slot) and head style for the tool access and seating surface; a recessed drive resists cam-out under power tools.
  • 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 7984. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.

Installation & Assembly Practice

  • This is a reduced-height head. The head, not the thread, limits what the screw will carry — ISO 7380-1 caps a button head at roughly 80% of the thread's capacity — so the thread's proof load overstates the assembly. Size the joint on the head, or use a cap screw where the full class strength is needed.
  • Match the driver exactly to the recess (PH ≠ PZ; hex key sizes per ISO 2936) and keep the tool axial — side load is the main cause of stripped drives.
  • In tapped holes, engage a thread length of at least 1× the nominal diameter in steel, 2× in aluminum.
  • Set power tools to a torque that seats the head without embedding it into the mating surface.

Common Selection Mistakes with Low Head Socket Cap Screws

  • Under-sizing the drive for the installation torque — a small recess at high torque strips before the screw is seated.
  • Using a countersunk head in thin sheet where the countersink removes most of the load-bearing material.
  • Specifying stainless in high-strength duty: A2-70 is roughly class 7 steel, not a 10.9 substitute.

Where Low Head Socket Cap Screws Are Not the Right Choice

Not for high-preload structural joints (use a property-class bolt and nut), and not in thin sheet where a self-drilling or self-tapping type suits better.

Custom manufacturing · Made to drawing

Need a low head socket cap screws outside the standard range?

Thread size and pitch, length, property class, drive form, head geometry and head marking are all specifiable — the standard part is where it starts, not where it stops. Made by cold heading or warm forging.

Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

Custom screw manufacturingSend a drawing

Technical Drawing

Customize the parameters below — every spec field is editable, and the drawing redraws to match the values you choose. Changing the size will snap the other fields to that size's standard values; you can then override any individual value.

Dimensioned line drawing of M3 Low Head Socket Cap Screws to DIN 7984. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.
Pitch P (mm)
0.5
b (mm)
12
Head diameter dk (mm)
5.5
da (mm)
3.6
ds_min (mm)
2.86
e (mm)
2.3
Head height k (mm)
2.0
r (mm)
0.1
Hex socket s (mm)
2.0
t (mm)
1.5
v (mm)
0.3
dw (mm)
4.84
Sends the selected values to the quote form below.

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The form below follows the current technical drawing configuration. Change the drawing values above and the request details update automatically.

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Specification
Business Information

Dimensions & Specifications (DIN 7984)

SizePitch P (mm)b (mm)Head diameter dk (mm)da (mm)ds_min (mm)e (mm)Head height k (mm)r (mm)Hex socket s (mm)t (mm)v (mm)dw (mm)Length range l (mm)Reference standard
M30.5125.53.62.862.32.00.12.01.50.34.845~20DIN 7984
M40.7147.04.73.822.872.80.22.52.30.46.26~25DIN 7984
M50.8168.55.74.823.443.50.23.02.70.57.78~30DIN 7984
M61.01810.06.85.824.584.00.254.03.00.69.210~40DIN 7984
M81.252213.09.27.75.725.00.45.03.80.812.0312~60DIN 7984
M101.52616.011.29.788.016.00.47.04.51.015.0316~70DIN 7984
M121.753018.013.711.739.157.00.68.05.01.217.0320~80DIN 7984
(M14)2.03421.015.713.7311.438.00.610.05.31.419.8330~80DIN 7984
M162.03824.017.715.7313.729.00.612.05.51.622.8330~80DIN 7984
(M18)2.54227.020.217.7313.7210.00.612.06.51.825.8340~100DIN 7984
M202.54630.022.419.6716.011.00.814.07.52.028.8340~100DIN 7984
(M22)2.55033.024.421.6716.012.00.814.08.02.231.6150~100DIN 7984
M243.05436.026.423.6719.4413.00.817.08.02.434.6150~100DIN 7984

Video: What Are Low Head Socket Cap Screws Used For? in use

Third-party video, selected automatically for this topic. It is not produced by Engineering Hardware and is not a specification source — use the tables on this page for dimensional data.

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
    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
    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
    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
    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 do I choose the right size of Low Head Socket Cap Screws?

Match the nominal size to the mating thread or hole. This product is available from M3 to M24; the full dimension table on this page lists each size.

What drive type do Low Head Socket Cap Screws use?

Drive depends on the head style — socket (hex key), cross (Phillips/Pozi) or slot. A recessed drive resists cam-out when driven with power tools; check the product head style on this page.

What material should Low Head Socket Cap Screws 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 Low Head Socket Cap Screws made to a recognized standard?

Yes — they are manufactured to DIN 7984, so dimensions are interchangeable between suppliers when you quote the standard on your order.

Can I get a quote for Low Head Socket Cap Screws 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.