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Screws · DIN 653 · Application guide

What Are Knurled Thumb Screws, Low Type Used For?

Typical applications, the industries that specify knurled thumb screws, low type, and how to choose the right size, material and finish for the joint.

Knurled Thumb Screws, Low Type are used for a low knurled thumb screw for hand tightening where head height is limited. They are manufactured to DIN 653, and selection is driven by the thread size, the fit and tolerance the assembly requires, and the service environment.

Primary duty
A low knurled thumb screw for hand tightening where head height is limited
Governing standard
DIN 653
Thread size range
M1 to M10
Category
Screws

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

What Are Knurled Thumb Screws, Low Type Used For? application image

Knurled Thumb Screws, Low Type (DIN 653) are specified where the joint requires a low knurled thumb screw for hand tightening where head height is limited. The sections below cover the typical end-uses by industry, the size and material decisions for each, assembly practice, and the applications this fastener type is not suited to. Stocked across roughly M1 to M10, they cover general to heavy-duty work.

Typical Applications for Knurled Thumb Screws, Low Type

The most common settings where these are specified:

  • Electronics: covers and card retainers opened by hand.
  • Photographic equipment: mounts and plates.
  • Workholding: light clamps and stops.
  • Display systems: panels changed without tools.

How to Specify Knurled Thumb Screws, Low Type for Your Application

  • Size: Match the nominal size to the mating thread or hole. This product spans M1–M10; 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 653. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.

Installation & Assembly Practice

  • 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 Knurled Thumb Screws, Low Type

  • 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 Knurled Thumb Screws, Low Type 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 knurled thumb screws, low type outside the standard range?

A non-standard screw is quoted from the drawing; where one already exists in the catalog, the special is usually a variation on its tooling. 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 M1 Knurled Thumb Screws, Low Type to DIN 653. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.
a_max (mm)
0.75
Head diameter dk (mm)
5.5
dk_max (mm)
5.74
dk_min (mm)
5.26
Head height k (mm)
1.5
k_min (mm)
1.25
r (mm)
0.5
Knurling
0.5
Length range l (mm)
2~6
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 653)

Sizea_max (mm)c (mm)Head diameter dk (mm)dk_max (mm)dk_min (mm)ds_nom_max (mm)ds_min (mm)e (mm)Head height k (mm)k_min (mm)r (mm)KnurlingLength range l (mm)Reference standard
M10.755.55.745.261.51.250.50.52~6DIN 653
M1.20.7566.245.761.51.250.50.52~8DIN 653
M1.40.977.296.7121.750.50.53~10DIN 653
M1.61.057.57.797.2121.750.50.53~12DIN 653
M21.299.298.7121.861.521.750.50.54~16DIN 653
M2.51.350.31111.3510.652.52.3622.52.250.50.65~18DIN 653
M31.50.31212.3511.6532.8622.52.250.50.66~20DIN 653
M42.10.41616.3515.6543.8233.53.20.50.68~25DIN 653
M52.40.42020.4219.5854.82343.710.610~30DIN 653
M630.52424.4223.5865.82454.710.612~30DIN 653
M83.750.63030.4229.5887.78565.720.616~35DIN 653
M104.50.83636.535.5109.78687.6420.620~40DIN 653
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 Knurled Thumb Screws, Low Type?

Match the nominal size to the mating thread or hole. This product is available from M1 to M10; the full dimension table on this page lists each size.

What drive type do Knurled Thumb Screws, Low Type 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 Knurled Thumb Screws, Low Type 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 Knurled Thumb Screws, Low Type made to a recognized standard?

Yes — they are manufactured to DIN 653, so dimensions are interchangeable between suppliers when you quote the standard on your order.

Can I get a quote for Knurled Thumb Screws, Low Type 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.