12 Point Screws manufacturers

12 Point Screws Specification

Typically, a 12-point bolt would be seen in the oil and gas industry because of the recessing head of the bolt. This will not be seen when they’re clamping together the end bolts. 12-point bolts are also prevalent in engine applications. Clamp load for engine applications are typically higher than most others, which a 12-point will help deliver.

Specification

All sizes of 12-point flange bolts have a minimum tensile strength of 170,000 psi, a minimum Rockwell hardness of C37, and a Class 3A thread fit. ASTM A387 Grade 9 is categorized as alloy steel.

12 Point Screw Features	12 Point Screw Sizes	12 Point Screw Materials
The driver of a 12-point screw uses two overlapped hexagon shapes, creating 12-points and a flanged underside. These are also referred to as ferry cap screws or 12 point flange screws. The advantages of this head style include: Higher torque capability compared to a socket head cap screw Lack of recess to trap fluid or debris. As the heads are generally smaller than a hex, 12-point screws are often used situations where installation space is tight and saving weight is critical. The overall disadvantage is the extra cost involved in forming the heads. The Controversy of 6 vs. 12 point Bolts There is much debate over which bolt is better. Some say that the more points a nut or bolt has – such as a 12-point bolt - the less chance you have to round it off. And that the additional contact points of a 12 point screw give you more surface to apply load. While the jury is out as to the accuracy of this, it’s the application that should dictate whether the benefits of a 12 point screw out weight the additional costs of making them.	#4 - 4" M3 - M100	12 Point - 17-4 PH 12 Point - A286 12 Point - AL-6XN 12 Point - Alloy 20 12 Point - Alloy 330 12 Point - Duplex Steel 12 Point - Hastelloy 12 Point - Incoloy 12 Point - Inconel 12 Point - Monel 12 Point - MP35N 12 Point - Titanium 12 Point - Waspaloy

12 Point Screw Features

12 Point Screw Sizes

12 Point Screw Materials

The driver of a 12-point screw uses two overlapped hexagon shapes, creating 12-points and a flanged underside. These are also referred to as ferry cap screws or 12 point flange screws. The advantages of this head style include:

Higher torque capability compared to a socket head cap screw
Lack of recess to trap fluid or debris.
As the heads are generally smaller than a hex, 12-point screws are often used situations where installation space is tight and saving weight is critical.

The overall disadvantage is the extra cost involved in forming the heads.

The Controversy of 6 vs. 12 point Bolts

There is much debate over which bolt is better. Some say that the more points a nut or bolt has – such as a 12-point bolt - the less chance you have to round it off. And that the additional contact points of a 12 point screw give you more surface to apply load. While the jury is out as to the accuracy of this, it’s the application that should dictate whether the benefits of a 12 point screw out weight the additional costs of making them.

#4 - 4"

M3 - M100

12 Point - 17-4 PH
12 Point - A286
12 Point - AL-6XN
12 Point - Alloy 20
12 Point - Alloy 330
12 Point - Duplex Steel
12 Point - Hastelloy
12 Point - Incoloy
12 Point - Inconel
12 Point - Monel
12 Point - MP35N
12 Point - Titanium
12 Point - Waspaloy

Other Types Of Bolts

Stainless Steel Bolts :
AISI 302, 304, 304L,316, 316L, 310, 317, 317L, 321, 347, 410, 420,904L etc.

Duplex & Super Duplex Steel Bolts :
ASTM / ASME A815 UNS No. S31803, UNS No. S 32205, UNS No. S 31254, UNS No. S 31550, UNS No. S 32750, and UNS No. S 32760

Carbon Steel Bolts :
ASTM A307, A193

Alloy Steel Bolts :
ASTM / ASME A/SA 193 / 194 B 6, B 7/ B 7M, B 16, 2, 2HM, 2H, GR 6, B 7, B 7M

Nickel Alloy Bolts :
ASTM / ASME SB 160 / 164 / 425 / 166 / 446 / 574 / 472 UNS 2200 (NICKEL 200) / UNS 2201 (NICKEL 201), UNS 4400 (MONEL 400), UNS 8825 (INCONEL 825), UNS 6600 (INCONEL 600) / UNS 6601 (INCONEL 601), UNS 6625 (INCONEL 625), UNS 10276 (HASTELLOY C 276), UNS 8020 (ALLOY 20 / 20 CB 3)

Dimensions for 12-Point Flange Bolts

12 Point Flange Bolt Dimensions
Nominal Size		Head Width		Flange Diameter	Head Height
Nominal Size		Across Flats	Across Corners	Flange Diameter	Head Height
Fraction	Decimal	Max	Min	Max	Max
1/4	0.2500	1/4	9/32	3/8	17/64
5/16	0.3125	5/16	11/32	15/32	5/16
3/8	0.3750	3/8	27/64	9/16	3/8
7/16	0.4375	7/16	31/64	21/32	7/16
1/2	0.5000	1/2	9/16	3/4	1/2
9/16	0.5625	9/16	41/64	27/32	9/16
5/8	0.6250	5/8	45/64	15/16	5/8
3/4	0.7500	3/4	27/32	1 1/8	3/4
7/8	0.8750	7/8	63/64	1 5/16	7/8
1	1.0000	1	1 1/8	1 1/2	1

12 Point Flange Bolt Dimensions. Nominal size in fractional and decimal inches, head width across flats and corners, flange diameter and head height, in inches. (Note: Minimum and maximum sizes are rounded to nearest 64th.)

Hexagon Flange Bolts

DIN 6921, Steel Grades: 8.8, 10.9

Finish: Self, Black, Bright Zinc, Hot Dip Galvanized

Nom. Dia. (d)		M6	M8	M10	M12	M14	M16	M20
Thread Pitch		1	1.25	1.5	1.75	2	2	2.5
Thread Length (b)	L < 125mm	18	22	26	30	34	38	46
	125-200mm	–	28	32	36	40	44	52
	L > 200mm	–	–	45	49	53	57	65
ds	Min.	6	8	10	12	14	16	20
ds	Max.	5.82	7.78	9.78	11.73	13.73	15.73	19.67
K	Max.	6.6	8.1	9.2	11.5	12.8	14.4	17.1
Flange Diameter		14.2	18	22.3	26.6	30.5	35	43
e	Min.	10.95	14.26	16.5	17.62	19.86	23.15	29.87
s	Min.	9.78	12.73	14.73	15.73	17.73	20.67	26.67
s	Max.	10	13	15	16	18	21	27