Square Thin Nuts Manufacturer in India | DIN 562 Thin Square Nuts

Overview

DIN 562 Thin Square Nuts: Manufacturer & Stockist

A square thin nut is the nut that hides inside the product. Pressed into a pocket of a housing or slid into a slot, it stays put while the screw is driven in from outside, and it takes little depth.

Exotic Alloy manufactures, stocks and exports square thin nuts from Mumbai, India, for electrical and electronics makers, plastic housing and appliance moulders, furniture and fixture makers, and fastener distributors. We supply across India and to Bahrain, the Gulf, Africa and South-East Asia.

Metric and inch

Metric thin square nuts follow DIN 562, product grade B, M1.6 to M10. The inch equivalent is the ASME B18.2.2 square machine screw nut, #0 to 3/8 in. For full-height square nuts see square nuts; for weldable ones square weld nuts.

DIN 562 ASME B18.2.2 M1.6 – M10 11H Stainless A2

Square thin nuts at a glance

Metric: DIN 562:2013, M1.6–M10, grade B
Inch: ASME B18.2.2, #0–3/8 in
Height: 0.5–0.64 d
Corners: e min 1.25–1.28 s
Steel: Hardness class 11H
Stainless: A2
Related: Square nuts, jam nuts, hex nuts

A DIN 562 M6 nut to scale. 10 mm across flats and only 3.2 mm high, with the corners cut back.

Specification

Square Thin Nut Specification

The range we manufacture, stock and export.

StandardsDIN 562; ASME B18.2.2 square machine screw nuts

SizesM1.6–M10; #0–3/8 in

ThreadMetric coarse; UNC, UNF

Product gradeB (DIN 562)

SteelHardness class 11H

StainlessA2 (304); A4 (316) on request

OtherBrass on request

FinishPlain, zinc plated

CertificationEN 10204 3.1; 3.2 on request

SupplyFrom stock, boxed by size

DIN 562

DIN 562 Thin Square Nut Dimensions

Product grade B, coarse thread, mm. (M3.5) is a non-preferred size.

Size	Pitch P	Spanner s max / min	Across corners e min	Height m max / min	m / d	kg / 1000
M1.6	0.35	3.2 / 2.9	4	1 / 0.6	0.62	0.08
M2	0.4	4 / 3.7	5	1.2 / 0.8	0.60	0.13
M2.5	0.45	5 / 4.7	6.3	1.6 / 1.2	0.64	0.27
M3	0.5	5.5 / 5.2	7	1.8 / 1.4	0.60	0.35
(M3.5)	0.6	6 / 5.7	7.6	2 / 1.6	0.57	0.44
M4	0.7	7 / 6.64	8.9	2.2 / 1.8	0.55	0.64
M5	0.8	8 / 7.64	10.2	2.7 / 2.3	0.54	1.06
M6	1	10 / 9.64	12.7	3.2 / 2.72	0.53	1.93
M8	1.25	13 / 12.57	16.5	4 / 3.52	0.50	4.01
M10	1.5	16 / 15.57	20.2	5 / 4.52	0.50	7.6

DIN 562:2013 (same values as 2000), confirmed by globalfastener and fasten.it. e min is across the cut-back corners. The 1987 edition also listed M10 with a 17 mm spanner. m / d is our calculation.

ASME inch

ASME B18.2.2 Square Machine Screw Nuts

Size	Basic ⌀, in	Threads UNC / UNF	Across flats F max / min, in	Across corners G max / min, in	Thickness H max / min, in
#0	0.060	– / 80	0.156 / 0.150	0.221 / 0.206	0.050 / 0.043
#1	0.073	64 / 72	0.156 / 0.150	0.221 / 0.206	0.050 / 0.043
#2	0.086	56 / 64	0.188 / 0.180	0.265 / 0.247	0.066 / 0.057
#3	0.099	48 / 56	0.188 / 0.180	0.265 / 0.247	0.066 / 0.057
#4	0.112	40 / 48	0.250 / 0.241	0.354 / 0.331	0.098 / 0.087
#5	0.125	40 / 44	0.312 / 0.302	0.442 / 0.415	0.114 / 0.102
#6	0.138	32 / 40	0.312 / 0.302	0.442 / 0.415	0.114 / 0.102
#8	0.164	32 / 36	0.344 / 0.332	0.486 / 0.456	0.130 / 0.117
#10	0.190	24 / 32	0.375 / 0.362	0.530 / 0.497	0.130 / 0.117
#12	0.216	24 / 28	0.438 / 0.423	0.619 / 0.581	0.161 / 0.148
1/4	0.250	20 / 28	0.438 / 0.423	0.619 / 0.581	0.193 / 0.178
5/16	0.312	18 / 24	0.562 / 0.545	0.795 / 0.748	0.225 / 0.208
3/8	0.375	16 / 24	0.625 / 0.607	0.884 / 0.833	0.257 / 0.239

ASME B18.2.2-2022 Table 1 (same values as 2015 Table 1-1), confirmed by fasten.it. #0 has UNF only. Pairs of sizes share one width across flats: #0 / #1, #2 / #3, #5 / #6 and #12 / 1/4; #12 and 1/4 differ in thickness. G max = F max × 1.414.

Thin vs regular

Thin Square Nut or Regular Square Nut

Same spanner, less height. DIN 562 against DIN 557 at M8.

Size	Spanner s	DIN 562 thin m max	DIN 557 regular m max	Thin / regular
M5	8	2.7	4	68 %
M6	10	3.2	5	64 %
M8	13	4	6.5	62 %
M10	16	5	8	62 %

0.5 to 0.64 d high. Smaller sizes are relatively taller. Hover a bar for the value.

Steel DIN 562 nuts carry hardness class 11H, a hardness rating, not a property class with a proof load: use them where the load is light, such as holding covers, terminals and fittings, and use DIN 557 or hex nuts where the joint carries load.

Pockets & slots

Designing a Pocket for a Square Thin Nut

Wider than the flats, narrower than the corners, deeper than the nut. Then the nut drops in and cannot turn.

Width: more than s max, less than e min.
Depth: at least m max, so the nut does not stand proud.

Screw: at least part thickness + m max for full thread engagement.
The finder below works out all three.

Finder

Square Thin Nut Finder: Pocket & Screw Length

Pick the nut and enter your part; get the pocket size, the screw length and the order line.

Nut & part

Standard

Size

Part to fix, mm

Your pocket, mm

Material

Quantity

Dimensions from the tables on this page; inch sizes converted at 25.4 mm. Pocket: s max < width < e min, depth ≥ m max. Shortest screw = part + m max, under the head. Leave the pocket empty to skip the check. Mass for steel DIN 562 nuts.

Result

> 8

mm pocket width, and under 10.2

7.7

mm shortest screw

Pocket depth:≥ 2.7 mm

Your pocket:9 mm: drops in, cannot turn

Spanner / height:8 / 2.3–2.7 mm

Thread / hole:M5 × 0.8, hole 5.5 mm (ISO 273)

Mass:≈ 5.3 kg

Designation:5000 pcs square nut DIN 562 – M5 – 11H

Materials

Square Thin Nut Materials & Finishes

Material	Class	Finish	Where
Steel	11H	Plain, zinc plated	Housings, panels, furniture fittings
Stainless A2 (304)	A2	Plain	Damp areas, food and medical equipment; as in the photo
Stainless A4 (316)	On request	Plain	Coastal and marine equipment
Brass	On request	Plain or nickel plated	Electrical terminals

DIN 562 names steel hardness class 11H and stainless A2 (DIN EN ISO 3506-2), and allows brass. One seller lists DIN 562 steel nuts as “strength class 4”; the standard uses hardness class 11H.

Steel

11H

Plain or zinc plated.

1010

Stainless

A2 · A4

As in the photo.

304 316

Brass

On request

Electrical terminals.

Brass

Manufacturing

How Our Square Thin Nuts Are Made

1

Strip / wire

Steel, stainless or brass, certified by heat.

2

Form

Square blank pressed, corners cut back.

3

Pierce

Hole pierced to tap-drill size.

4

Tap

Metric, UNC or UNF thread.

5

Finish

Zinc plated or passivated.

6

Inspect

Thread, flats and height checked.

Applications

Where Our Square Thin Nuts Are Used

Electrical

Switchgear, sockets and terminal blocks.

Electronics

Moulded housings and enclosures.

Appliances

Plastic covers and panels.

Furniture

Fittings and knock-down joints.

Lighting

Fixtures and mounting rails.

Vehicles

Trim and interior panels.

Quality & testing

Square Thin Nut Inspection & Certification

Check	Method	Applied to
Thread	GO / NOT GO plug gauges	Every lot
s, e, m	Calipers, micrometer	Every lot
Hardness	Vickers, class 11H	Steel lots
Coating	Thickness gauge	Plated lots
Material	Heat certificate, PMI on request	Every heat
Flatness / burrs	Visual	Every lot

Every shipment includes

EN 10204 3.1 certificate
Lot number on every box
Packing list by size

On request

EN 10204 3.2 with third-party inspection
Salt spray tests on plated nuts
Small packs for assembly lines

FAQ

Square Thin Nut Questions, Answered

A low, four-sided nut, made to DIN 562 from M1.6 to M10. It is 0.5 to 0.64 times as high as the thread diameter and fits into a slot or moulded pocket, where its flats stop it turning while a screw is driven in from the other side.

8 mm across flats, at least 10.2 mm across the corners, and 2.3 to 2.7 mm high. 1000 steel nuts weigh about 1.06 kg.

At M5, M6, M8 and M10 (16 mm) both use the same spanner, but the thin nut is only 62 to 68 % as high: 4 mm against 6.5 mm at M8. DIN 562 also goes down to M1.6, while DIN 557 starts at M5.

Steel DIN 562 nuts are hardness class 11H, a hardness rating rather than a property class with a proof load, because a nut this thin cannot carry the full load of a bolt. Stainless nuts are A2; brass on request.

Wider than the nut across flats so it drops in, narrower than its corners so it cannot turn, and at least as deep as the nut is high. For DIN 562 M5: wider than 8 mm, narrower than 10.2 mm, at least 2.7 mm deep; a 9 mm square pocket 3 mm deep works.

DIN 562 allows the corners to be cut back: the minimum across corners is about 1.25 to 1.28 times the width across flats, against 1.41 times for a sharp square. Rounded corners slide into pockets more easily.

ASME B18.2.2 square machine screw nuts, #0 to 3/8 in, with UNC and UNF threads. A #10 nut is 3/8 in across flats and 0.117 to 0.130 in thick.

The 2013 edition has the same dimensions as 2000. The 1987 edition also offered M10 with a 17 mm spanner; since 2000, M10 is 16 mm only.

Metric and inch

Nut & part

Result

Steel

Stainless

Brass

Strip / wire

Form

Pierce

Tap

Finish

Inspect

Electrical

Electronics

Appliances

Furniture

Lighting

Vehicles

Every shipment includes

On request

What is a square thin nut?

What are the dimensions of a DIN 562 M5 nut?

How does a thin square nut differ from a DIN 557 square nut?

Which strength class are DIN 562 nuts?

How big should the pocket for a square nut be?

Why are the corners of a thin square nut rounded?

What is the inch equivalent?

Did DIN 562 change?

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