12 Spline Flange Screw

The 12 spline flange screw of Xiaoguo® has a 12-point head design that perfectly matches the Ring spanner. Even in a confined space, it can still be operated. Compared to the hexagonal head， the operating space is reduced by 50%. Come and inquire about the sample price to experience the quick installation.

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Product Description

Introduction to Materials

The material selection for 12 spline flange screw is very diverse, mainly falling into four categories: carbon steel, alloy steel, stainless steel, and special alloys. The choice of material depends on your specific requirements for strength, corrosion resistance, working temperature, and cost.

（1）Carbon Steel

Carbon steel is the most widely used and cost-effective option. Through various heat treatment processes (quenching + tempering), different strength grades ranging from 4.8 to 12.9 can be achieved to meet various load requirements. It is suitable for general industry, automotive structures, construction, and general machinery.

（2）Alloy Steel

By adding elements such as chromium, molybdenum and nickel to carbon steel and then undergoing precise heat treatment, the mechanical properties of the steel can be significantly improved. The strength is extremely high, and it has excellent fatigue resistance and impact resistance properties. The 12 spline flange screw of Alloy Steel are widely used in automotive suspension systems, engine interiors, wind turbine tower bolts, and heavy construction machinery.

12 Spline Flange Screw

（3）Stainless Steel

The core advantage of stainless steel lies in its inherent corrosion resistance. Among them, 304 (A2) is the most common type and is suitable for food processing and general outdoor environments; while 316 (A4) has been specially designed by adding molybdenum, making the 12 spline flange screw particularly suitable for high salt spray environments and highly corrosive environments, such as in the ocean, coastal areas, or chemical plants, etc.

（4）Special alloy

The special alloy materials include Chrome-Moly, Ti, high-temperature resistant alloys, aluminum alloys, brass, etc. They are designed to meet the specific performance requirements of customers, such as high-temperature resistance, lightweight, conductivity, and non-magnetism. Mainly for special industrial fields such as aerospace, racing, medical, petrochemicals, and electrical.

12 Spline Flange Screw

Mon	M22	M24	M27	M30	M33	M36	M39	M42	M45	M48	M52
P	2.5	3	3	3.5	3.5	4	4	4.5	4.5	5	5
dc max	33.3	38.1	38.1	42.8	47.5	52.3	57	61.7	66.5	76	76
dc min	32.68	37.48	37.48	42.18	46.88	51.56	56.26	60.96	65.76	75.26	75.26
ds max	22	24	27	30	33.0	36	39	42.0	45.0	48	52
ds min	21.79	23.79	26.79	29.79	32.75	35.75	38.75	41.75	44.75	47.75	51.7
e min	25.4	27.7	27.7	34.6	36.90	41.60	47.30	47.30	53.10	57.70	57.70
h max	6.9	7.98	7.98	9.21	9.62	10.82	12.71	12.56	15.65	16.1	16.1
h min	6.54	7.35	7.35	8.78	9.19	10.39	12.28	12.13	15.13	15.58	15.58
k max	22.36	25.56	25.56	28.96	32.0	35.2	38.3	41.4	44.7	51.03	51.03
k min	22.04	25.24	25.24	28.54	31.6	34.80	37.90	41.00	44.30	50.57	50.57
r max	1	1.2	1.20	1.4	1.60	1.60	1.80	1.80	2.00	2.20	2.20
r min	0.75	0.95	0.95	1.15	1.35	1.35	1.55	1.55	1.75	1.82	1.82
s max	22	24	24	30	32.00	36.00	41.00	41.00	46.0	50.0	50.0
s min	21.79	23.79	23.79	29.79	31.75	35.75	40.75	40.75	45.75	49.75	49.75

Performance grade and tensile strength

The performance grade is the core indicator determining the strength of the 12 spline flange screw. The common performance grades and their corresponding tensile strengths are as follows:

（1）8.8 grade: The minimum tensile strength is approximately 800 MPa (about 116,000 psi), which falls within the medium-high strength range and is the most widely used.

（2）10.9 grade: The minimum tensile strength is approximately 1,000 MPa (about 145,000 psi), suitable for scenarios requiring high-strength connections.

（3）12.9 grade: The minimum tensile strength is approximately 1,220 MPa (about 177,000 psi), which is one of the highest strength levels among alloy steels.

（4）Mandarin Grade 5: The tensile strength is approximately 120,000 psi, which is equivalent to the metric 8.8 grade.

（5）American Standard Grade 8: The tensile strength is approximately 150,000 psi, which is equivalent to the metric 10.9 grade.