M2 Dog Point Set Screw (Dog Point Grub Screw), ISO 4028

A headless M2 × 0.4 dog point set screw (ISO 4028), turned with a 0.9 mm hex key. Available as 7 lengths from 2.5 to 10 mm, each as simplified and threaded STEP.

How these parts are made, and what the levels mean: read the method

• Also searched as: M2 set screw, M2 x 2.5 to M2 x 10 set screws
• Model id: iso4028-m2
• Standard: ISO 4028:2003 · thread M2 × 0.4, ISO metric coarse, right hand

Lengths

Length (mm)	Part key	Simplified	Threaded
2.5	iso4028-m2x2-5	STEP	STEP
3	iso4028-m2x3	STEP	STEP
4	iso4028-m2x4	STEP	STEP
5	iso4028-m2x5	STEP	STEP
6	iso4028-m2x6	STEP	STEP
8	iso4028-m2x8	STEP	STEP
10	iso4028-m2x10	STEP	STEP

Dimensions

Symbol	Name	min	nom	max	Modeled	Rule	Level
P	Thread pitch		0.4		0.4	nominal	L1
s	Socket width across flats	0.887	0.9	0.913	0.9	midpoint of min–max	L1
e	Socket width across corners	1.011			1.011	single limit (min), modeled at the limit	L1
t_short	Socket depth, short screws	0.8			0.8	single limit (min), modeled at the limit	L1
t_long	Socket depth, long screws	1.7			1.7	single limit (min), modeled at the limit	L1
dp	Point diameter, flat and dog point	0.75		1	0.875	midpoint of min–max	L1
dt	Truncation diameter, cone point			0.5	0.5	single limit (max), modeled at the limit	L1
dz	Cup diameter, cup point	0.75		1	0.875	midpoint of min–max	L1
z_short	Dog length, short dog point	0.5		0.75	0.625	midpoint of min–max	L1
z_long	Dog length, long dog point	1		1.25	1.125	midpoint of min–max	L1
fl_angle	Flat point chamfer angle			50	50	single limit (max), modeled at the limit	L2
cone_angle	Cone point included angle, long lengths		90		90	nominal	L2
cone_angle_short	Cone point included angle, short lengths		120		120	nominal	L1
dog_angle	Dog point chamfer angle			50	50	single limit (max), modeled at the limit	L2
cp_angle	Cup point outer chamfer angle			50	50	single limit (max), modeled at the limit	L2
cup_angle	Cup recess included angle		120 ref		120	reference value	L2
P	Coarse thread pitch		0.4		0.4	nominal	L1
tap_drill	Tap drill diameter		1.6		1.6	nominal	L1
d1	Basic minor diameter		1.5669872		1.5669872	nominal	L1
ch_angle	Chamfered end angle			50	50	single limit (max), modeled at the limit	L2
dh_fine	Clearance hole, fine series		2.2		2.2	nominal	L1
dh_medium	Clearance hole, medium series		2.4		2.4	nominal	L1
dh_coarse	Clearance hole, coarse series		2.6		2.6	nominal	L1

Thread and holes

• Tap drill: 1.6 mm (method: d − P), L1, sources amesweb-tap-drill, rule-tap-drill.
• Clearance hole (ISO 273): close 2.2, normal 2.4, loose 2.6 mm (L1: fine, medium and coarse series (albany-clearance, wikipedia-de-clearance)).

Drawing

As a PDF: CC-ISO4028-SZ-M2.pdf.

Goes with the M2 dog point set screw

• Hex key: 0.9 mm, the socket's nominal width across flats (s) in the table above.

The M2 dog point set screw beside the M2.5

The M2 is the smallest of the 7 ISO 4028 dog point set screws published here, from M2 to M8.

• Thread pitch (P): 0.4 mm on the M2 dog point set screw, against 0.45 mm on the M2.5.
• Socket width across flats (s): 0.9 mm on the M2 dog point set screw, against 1.3 mm on the M2.5.
• Socket width across corners (e): at least 1.011 mm on the M2 dog point set screw, against at least 1.454 mm on the M2.5.
• Socket depth, short screws (t_short): at least 0.8 mm on the M2 dog point set screw, against at least 1.2 mm on the M2.5.
• Socket depth, long screws (t_long): at least 1.7 mm on the M2 dog point set screw, against at least 2 mm on the M2.5.
• Point diameter, flat and dog point (dp): 0.75 to 1 mm on the M2 dog point set screw, against 1.25 to 1.5 mm on the M2.5.
• Truncation diameter, cone point (dt): up to 0.5 mm on the M2 dog point set screw, against up to 0.65 mm on the M2.5.
• Cup diameter, cup point (dz): 0.75 to 1 mm on the M2 dog point set screw, against 0.95 to 1.2 mm on the M2.5.

Other sizes

• One size larger: M2.5 Dog Point Set Screw (Dog Point Grub Screw), ISO 4028, 1.3 mm hex key.

Documents

• CC-ISO4028-DS-M2.pdf: M2 datasheet: values with levels, lengths, sources
• CC-ISO4028-SZ-M2.pdf: M2 drawing: this size's values on the views
• parts.json: the part record of every length (the platform contract)

Sources

accu-iso4027, albany-clearance, amesweb-iso4026-4029, amesweb-tap-drill, fasten-it-iso4026, fasten-it-iso4027, fasten-it-iso4028, fasten-it-iso4029, fuller-iso4026, fuller-iso4027, fuller-iso4028, fuller-iso4029, iso4753-2011-sample, iso4753-2011-sample-text, rule-basic-minor, rule-tap-drill, wikipedia-de-clearance, wikipedia-iso261. Full citations: the method page and this size's datasheet.

Found an error? Use the feedback section on this page.