ORDERING METRIC SIZES

How to Order  | Conversion  | Metric-SAE Equivalents Table | Metric Threads  | Length of threads | Screw dimensions | Spacer Tolerances

HOW TO ORDER METRIC PARTS

ASM makes it easy to order metric hardware, including metric screws, spacers, and standoffs. Once you have selected one of our American Standard Parts, you just need to add your metric requirement in the RFQ. For example, for a Threaded Spacer, the metric requirement might be “M 3.5 x 0.6 Thread”.  Below you’ll find details on conversions and dimensions that will help you order parts like metric screws and standoffs.

How to order metric male/female standoff

Once you have selected one of our American Standard Parts, you just need to add your metric requirement in the RFQ. For example, “M3.0 x .5 Thread”.

Metric Thread Min. Depth
A B
2.5 x 0.45 3.97 3.97
3.0 x 0.50 4.76 6.35
3.5 x 0.60 6.35 9.53
4.0 x 0.70 9.53 11.10
5.0 x 0.80 9.53 12.70
6.0 x 1.00 12.70 15.00
8.0 x 1.25 12.70 15.00

If you need a longer Male Thread than shown in the table above, you may add your requirement. For example, “B = 3.0 x .5 Thread, B = 7.5 MM Length

NOTE: When the body length L is less than or equal to the thread depth A, we will provide the maximum number of threads possible.

CONVERSION (SAE to Metric & Metric to SAE)

To convert inches to millimeters, multiply inches x 25.4. To convert millimeters to inches multiply millimeters x 0.039370.

SPACER TOLERANCES

Tolerances in the manufacture of Standoffs and Spacers. Length: up to 100MM long ±.13 MM. O.D. ±.152 MM

METRIC THREADS

Clearance Hole Recommended Thread Sizes Depth of Thread
Recommended blind hole thread engagement(Drilled and Tapped both ends)
Diameter x Pitch Clearance Hole Range Diameter x Pitch Thread Size Screw Engagement
1.6 x 0.35 1.8 – 2.1 M1.6 x 0.35 M 2.5 4.8 mm
2.0 x 0.40 2.2 – 2.8 2.0 x 0.40 3.0 8.4
2.5 x 0.45 2.7 – 3.1 2.5 x 0.45 3.5 9.5
3.0 x 0.50 3.2 – 3.6 3.0 x 0.50 4.0 11.1
3.5 x 0.60 3.7 – 4.2 3.5 x 0.60 5.0 12.7
4.0 x 0.70 4.2 – 4.8 4.0 x 0.70 6.0 14.3
5.0 x 0.80 5.3 – 6.0 5.0 x 0.80 7.0 14.3
6.0 x 1.00 6.3 – 7.0 6.0 x 1.00
6.3 x 1.00 6.7 – 7.5 6.3 x 1.00
8.0 x 1.25 8.5 – 9.5 8.0 x 1.25
10.0 x 1.5
12.0 x 1.75

LENGTH OF THREAD

Brass, Aluminum & Steel Parts: M2.5 thread is tapped thru 15.99 MM in length. M3 and larger thread is tapped thru 25.4 MM in length.

Stainless Steel & Nylon Parts: M2.5 thread is tapped thru 9.6 MM in length M3 thread is tapped thru 12.7 MM in length. M3.5 and larger threads are tapped thru 25.4 MM in lengths. For lengths longer than specified above, see Depth of Thread Chart.

SCREW DIMENSIONS

Oval Head Machine Screws

Metric screw dimensions in millimeters, including M2.5 and M4 screws.

Thread Size ‘D’ M2 M2.5 M3 M4 M5 M6
Head Height, Max “K” 1.7 2.1 2.4 3.7 3.9 4.7
Head Dia, Max “D2” 4.4 5.5 6.3 9.4 10.4 12.6
Driver Size “No.” 1 1 1 2 2 3

Pan Head Slotted Machine Screws

Dimensions in millimeters

Thread Size ‘D’ M3 M4 M5 M6
Head Height, Max “K” 1.8 2.4 3 3.6
Head Dia, Max “D2” 6 8 10 12
Driver Size “No.” .50 .70 .80 1

Pan Head Crossed Recessed Machine Screws

Metric screw dimensions in millimeters

Thread Size ‘D’ M2 M2.5 M3 M4 M5 M6
Head Height, Max “K” 1.6 2 2.4 3.1 3.8 4.6
Head Dia, Max “D2” 4 5 6 8 10 12
Driver Size “No.” 1 1 1 2 2 3

Flat Head Machine Screws

Metric screw dimensions in millimeters

Thread Size ‘D’ M2 M2.5 M3 M4 M5 M6 M8 M10
Head Height, Max “K” 1.2 1.5 1.65 2.2 2.5 3 4 5
Head Dia, Max “D2” 3.8 4.7 5.6 7.5 9.2 11 14.5 18
Pitch “P” .40 .45 .50 .7 .8 1 1.25 1.50

Socket Head Cap Screws

Dimensions in millimeters

Thread Size ‘D’ M3 M4 M5 M6 M8 M10 M12 M14 M16 M20
Head Height, Max “K” 3 4 5 6 8 10 12 14 16 20
Head Dia, Max “D2” 5.5 7 8.5 10 13 16 10 21 24 30
Hex Key Sz “S” 2.5 3 4 5 6 8 10 12 14 17

Hexagon Head Cap Screws

Dimensions in millimeters

Thread Size ‘D’ M4 M5 M6 M8 M10 M12 M14 M16 M20 M24
Head Height, Max “K” 2.8 3.5 4 5.5 7 8 9 10 13 15
Across Flats, “S” .7 8 10 13 17 19 22 24 30 36
Pitch, “P” .7 .8 1 1.25 1.5 1.75 2 2 2.5 3

Button Head Screws

Dimensions in millimeters

Head Dia, Max ‘B’ Head Height, Max ‘R’ Socket Size, Nom ‘S’
5.7 1.65 2
7.6 2.20 2.5
9.5 2.75 3
10.5 3.30 4
14.0 4.40 5
17.5 5.50 6
21.0 6.60 8
28.0 8.80 10

Important Data, Metric, Machine Screws

Dimensions in millimeters

Nominal Screw Length Tolerance on Length, mm
to 3 mm incl. .2
over 3 to 10 mm .3
over 10 to 16 mm .4
over 16 to 50 mm .5
over 50 mm 1.0

Position of Head: The axis of the head shall be located at a true position relative to the axis of the screw shank within a tolerance zone having a diameter equivalent to 6% of the specified maximum head diameter, or the specified maximum width across flats of hex and hex flange heads, regardless of feature size.

All tolerances are plus and minus.

ASM METRIC – SAE EQUIVALENTS

8ths/4ths 16ths 32nds 64ths SAE Decimal Millimeters
1/64 .016 0.397
1/32 .031 0.794
3/64 .047 1.191
1/16 .062 1.588
5/64 .078 1.984
3/32 .094 2.381
7/64 .109 2.778
1/8 .125 3.175
9/64 .141 3.572
5/32 .156 3.969
11/64 .172 4.366
3/16 .188 4.763
13/64 .203 5.159
7/32 .219 5.556
15/64 .234 5.953
1/4 .250 6.350
17/64 .266 .266 6.747
9/32 .281 7.144
19/64 .297 7.541
5/16 .312 7.938
21/64 .328 8.334
11/32 .344 8.731
23/64 .359 9.128
3/8 .375 9.525
25/64 .391 9.922
13/32 .406 10.319
27/64 .422 10.716
7/16 .438 11.113
29/64 .453 11.509
15/32 .469 11.906
31/64 .484 12.303
1/2 .500 12.700
33/64 .516 13.097
17/32 .531 13.494
35/64 .547 13.891
9/16 .562 14.288
37/64 .578 14.684
19/32 .594 15.081
39/64 .609 15.478
5/8 .625 15.875
41/64 .641 16.272
21/32 .656 16.669
43/64 .672 17.066
11/16 .688 17.463
45/64 .703 17.859
23/32 .719 18.256
47/64 .734 18.653
3/4 .750 19.050
49/64 .766 19.447
25/32 .781 19.844
51/64 .797 20.241
13/16 .812 20.638
53/64 .828 21.034
27/32 .844 21.431
55/64 .859 21.828
7/8 .875 22.225
57/64 .891 22.622
29/32 .906 23.019
59/64 .922 23.416
15/16 .938 23.813
61/64 .953 24.209
31/32 .969 24.606
63/64 .984 25.003
1 1.000 25.400