Bolting Dimensions

Dimensions for Hex Head Bolt DIN931

Hex Head Bolts are part threaded.

*Thread lengths listed are a guide value for bolts under 125mm. For bolts longer than 125mm and shorter than 200mm add additional 6mm of thread. For bolts 200mm and longer add 19mm to the thread lengths listed. NB shortest bolt lengths may be or appear to be fully threaded.

Diameter	Pitch	Thread Length*	Head Depth	Across Flats
M4	0.7mm	14mm	2.8mm	7mm
M5	0.8mm	16mm	3.5mm	8mm
M6	1.0mm	18mm	4mm	10mm
M7	1.0mm	20mm	4.8mm	11mm
M8	1.25mm	22mm	5.3mm	13mm
M10	1.5mm	26mm	6.4mm	17mm
M12	1.75mm	30mm	7.5mm	19mm
M14	2mm	14mm	8.8mm	22mm
M16	2mm	38mm	10mm	24mm
M18	2.5mm	42mm	11.5mm	27mm
M20	2.5mm	46mm	12.5mm	30mm
M22	2.5mm	50mm	14mm	32mm
M24	3.0mm	54mm	15mm	36mm
M27	3.0mm	54mm	15mm	41mm
M30	3.5mm	66mm	18.7mm	46mm
M33	3.5mm	72mm	21mm	50mm
M36	4mm	78mm	22.5mm	55mm
M39	4mm	84mm	25mm	60mm
M42	4.5mm	90mm	26mm	65mm
M45	4.5mm	96mm	28mm	70mm
M48	5mm	102mm	30mm	75mm

Dimensions for Hex Head Setscrew DIN933

Hex Setscrew Bolts are fully threaded: all other dimensions as Hex Bolt above (thread length not appliable).

Dimensions for Pozi Countersunk Machine Screws DIN965

Diameter	Pitch	Head Diameter	Head Depth	No. Cross Recess
M1.6	0.35mm	3.0mm	0.96mm	0
M2	0.4mm	3.8mm	1.2mm	1
M2.5	0.45mm	4.7mm	1.5mm	1
M3	0.5mm	5.6mm	1.65mm	1
M4	0.7mm	7.5mm	2.2mm	2
M5	0.8mm	9.2mm	2.5mm	2
M6	1.0mm	11.0mm	3.0mm	3
M8	1.25mm	14.5mm	4.0mm	4
M10	1.5mm	18.0mm	5.0mm	4

Dimensions for Slotted Countersunk Machine Screws DIN963

Diameter	Pitch	Head Diameter	Head Depth	Width of Slot
M1.0	0.25mm	1.9mm	0.6mm	0.25mm
M1.6	0.35mm	3.0mm	0.96mm	0.4mm
M2	0.4mm	3.8mm	1.2mm	0.5mm
M2.5	0.45mm	4.7mm	1.5mm	0.6mm
M3	0.5mm	5.6mm	1.65mm	0.8mm
M4	0.7mm	7.5mm	2.2mm	1.0mm
M5	0.8mm	9.2mm	2.5mm	1.2mm
M6	1.0mm	11.0mm	3.0mm	1.6mm
M8	1.25mm	14.5mm	4.0mm	2.0mm
M10	1.5mm	18.0mm	5.0mm	2.5mm
M12	1.75mm	22.0mm	6.0mm	3.0mm
M14	2.0mm	25.0mm	7.0mm	3.0mm
M16	2.0mm	29.0mm	8.0mm	4.0mm
M18	2.5mm	33.0mm	9.0mm	4.0mm
M20	2.5mm	36.0mm	10.0mm	5.0mm

Dimensions for Pozi Pan Machine Screws DIN7985

Diameter	Pitch	Head Diameter	Head Height	No. of Cross Recess
M1.6	0.35mm	3.2mm	1.3mm	0
M2	0.4mm	4.0mm	1.6mm	1
M2.5	0.45mm	5.0mm	2.0mm	1
M3	0.5mm	6.0mm	2.4mm	1
M4	0.7mm	8.0mm	3.1mm	2
M5	0.8mm	10.0mm	3.8mm	2
M6	1.0mm	12.0mm	4.6mm	3
M8	1.25mm	16.0mm	6.0mm	4
M10	1.5mm	20.0mm	7.5mm	4

Dimensions for Slotted Pan Machine Screws DIN85

Diameter	Pitch	Head Diameter	Head Height	Width of Slot
M2 (≠ DIN)	0.4mm	4.0mm	1.3mm	0.5mm
M2.5 (≠ DIN)	0.45mm	5.0mm	1.5mm	0.6mm
M3	0.5mm	6.0mm	2.1mm	1.0mm
M4	0.7mm	8.0mm	2.4mm	1.2mm
M5	0.8mm	10.0mm	3.0mm	1.2mm
M6	1.0mm	12.0mm	3.6mm	1.6mm
M8	1.25mm	16.0mm	4.8mm	2.0mm
M10	1.5mm	20.0mm	6.0mm	2.5mm

Dimensions for Slotted Cheese Machine Screws DIN84

Diameter	Pitch	Head Diameter	Head Height	Width of Slot
M1	0.25mm	2.0mm	0.7mm	0.25mm
M1.2	0.25mm	2.3mm	0.8mm	0.3mm
M1.4	0.3mm	2.6mm	0.9mm	0.3mm
M1.6	0.35mm	3.0mm	1.0mm	0.4mm
M1.7 (≠ DIN)	0.35mm	3.4mm	1.2mm	0.4mm
M2	0.4mm	3.8mm	1.3mm	0.5mm
M2.5	0.45mm	4.5mm	1.6mm	0.6mm
M3	0.5mm	5.5mm	2.0mm	0.8mm
M4	0.7mm	7.0mm	2.6mm	1.2mm
M5	0.8mm	8.5mm	3.3mm	1.2mm
M6	1.0mm	10.0mm	3.9mm	1.6mm
M8	1.25mm	13.0mm	5.0mm	2.0mm
M10	1.5mm	16.0mm	6.0mm	2.5mm
M12(≠ DIN)	1.75mm	18.0mm	7.0mm	3.0mm

Dimensions for Pozi Raised Countersunk Machine Screws DIN966

Diameter	Pitch	dk	k (max.)	f ≈	No. cross recess
M2	0.4mm	3.8mm	1.2mm	0.5mm	1
M2.5	0.45mm	4.7mm	1.5mm	0.6mm	1
M3	0.5mm	5.6mm	1.65mm	0.75mm	1
M4	0.7mm	7.5mm	2.2mm	1.0mm	2
M5	0.8mm	9.2mm	2.5mm	1.25mm	2
M6	1.0mm	11.0mm	3.0mm	1.5mm	3
M8	1.25mm	14.5mm	4.0mm	2.0mm	4

Dimensions for Slotted Raised Countersunk Machine Screws DIN964

Diameter	Pitch	dk	k (max.)	f ≈	No. cross recess
M2	0.4mm	3.8mm	1.2mm	0.5mm	0.5mm
M2.5	0.45mm	4.7mm	1.5mm	0.6mm	0.6mm
M3	0.5mm	5.6mm	1.65mm	0.75mm	0.8mm
M4	0.7mm	7.5mm	2.2mm	1.0mm	1.0mm
M5	0.8mm	9.2mm	2.5mm	1.25mm	1.2mm
M6	1.0mm	11.0mm	3.0mm	1.5mm	1.6mm
M8	1.25mm	14.5mm	4.0mm	2.0mm	2.0mm
M10	1.5mm	18.0mm	5.0mm	2.5mm	2.5mm

Dimensions for Coachbolts DIN603

Diameter	Pitch	Head diameter	Head Depth	Width of square	Depth of square
M5	0.8mm	13.55mm	3.3mm	5.48mm	4.1mm
M6	1.0mm	16.55mm	3.88mm	6.48mm	4.6mm
M8	1.25mm	20.65mm	4.88mm	8.58mm	5.6mm
M10	1.5mm	24.65mm	5.38mm	10.58mm	6.6mm
M12	1.75mm	30.65mm	6.95mm	12.7mm	8.75mm
M16	2.0mm	38.8mm	8.95mm	16.7mm	12.9mm

Dimensions for Standard U Bolts

Nominal Pipe Size	Thread Size	Between Centres	Depth of U	Thread Length
1/2"	M6	28mm	48mm	30mm
3/4"	M6	34mm	53mm	30mm
1"	M6	41mm	60mm	30mm
1.1/4"	M10	54mm	67mm	30mm
1.1/2"	M10	60mm	85mm	35mm
2"	M10	75mm	95mm	35mm
2.1/2"	M12	90mm	124mm	55mm
3"	M12	102mm	126mm	50mm
4"	M12	131mm	144.5mm	50mm
5"	M12	156mm	182mm	50mm
6"	M12	182mm	210mm	50mm
8"	M16	240mm	252mm	50mm
10"	M16	292mm	318mm	50mm
12"	M16	343mm	363.6mm	50mm