304 Vs 316 Stainless Steel Flanges, Bolts, And Nuts

If you are looking for high-quality stainless steel fasteners and flanges, understanding the differences between 304 and 316 stainless steel is crucial for selecting the right material for your application. Flange connections primarily consist of flanges, bolts, and gaskets. Flanges are typically installed using bolts. SH/T3406, "Technical Specification for Steel Pipe Flanges in the Petrochemical Industry," specifies the flange thickness, bolt hole diameter, bolt size, and bolt specifications for flanges of different sizes, dimensions, and pressure ratings, for engineers to reference during design, construction, and acceptance processes.

GNEE offers a complete range of 304 and 316 stainless steel flanges, bolts, and nuts. All products are certified and suitable for industries such as industrial, marine, chemical, and food processing.

 

Feature / Property	304 Stainless Steel	316 Stainless Steel
UNS Number	S30400	S31600
Chemical Composition	Cr 18–20%, Ni 8–10.5%, C ≤0.08%	Cr 16–18%, Ni 10–14%, Mo 2–3%, C ≤0.08%
Corrosion Resistance	Good in most environments	Excellent, especially in chloride-rich or marine environments
Mechanical Strength	Tensile: 515–720 MPa	Tensile: 515–720 MPa
Yield Strength	≥205 MPa	≥205 MPa
Elongation	≥40%	≥40%

Fasteners (Bolts & Nuts):

Both grades available in ASTM A193, A194, A276 standards.

Sizes: M6 – M100 (customizable lengths).

Surface finish: Bright, polished, or passivated.

Certificates: ISO 9001, SGS, BV, MTC 3.1.

 

Specification	PN2.0					PN5.0
	Thickness	Hole Diameter	Bolt	Nut	Quantity	Thickness	Hole Diameter	Bolt	Nut	Quantity
DN15	11.5	16	M14	24	4	14.5	16	M14	24	4
DN20	13	16	M14	24	4	16	18	M16	27	4
DN25	14.5	16	M14	24	4	17.5	18	M16	27	4
DN32	16	16	M14	24	4	19.5	18	M16	27	4
DN40	17.5	16	M14	24	4	21	22	M20	34	4
DN50	19.5	18	M16	27	4	22.5	18	M16	27	8
DN65	22.5	18	M16	27	4	25.5	22	M20	34	8
DN80	24	18	M16	27	4	29	22	M20	34	8
DN100	24	18	M16	27	8	32	22	M20	34	8
DN125	24	22	M20	34	8	35	22	M20	34	8
DN150	25.5	22	M20	34	8	37	22	M20	34	12
DN200	29	22	M20	34	8	41.5	26	M24	41	12
DN250	30.5	26	M24	41	12	48	30	M27	46	16
DN300	32	26	M24	41	12	51	33	M30	50	16
DN350	35	30	M27	46	12	54	33	M30	50	20
DN400	37	30	M27	46	16	57.5	36	M33	55	20
DN450	40	30	M30	50	16	60.5	36	M33	55	24
DN500	43	33	M30	50	20	63.5	36	M33	55	24
DN550	46	36	M33	55	20	66.5	42	M39	65	24
DN600	48	36	M33	55	20	42	39	M39	65	24

 

Specification	PN10.0					PN15.0
	Thickness	Hole Diameter	Bolt	Nut	Quantity	Thickness	Hole Diameter	Bolt	Nut	Quantity
DN15	14.5	16	M14	24	4	22.5	22	M20	34	4
DN20	16	18	M16	27	4	25.5	22	M20	34	4
DN25	17.5	18	M16	27	4	29	26	M24	41	4
DN32	21	18	M16	27	4	29	26	M24	41	4
DN40	22.5	22	M20	34	4	32	30	M27	46	4
DN50	25.5	18	M16	27	8	38.5	26	M24	41	8
DN65	29	22	M20	34	8	41.5	30	M27	46	8
DN80	32	22	M20	34	8	38.5	26	M24	41	8
DN100	38.5	26	M24	41	8	44.5	33	M30	50	8
DN125	44.5	30	M27	46	8	51	36	M33	55	8
DN150	48	30	M27	46	12	56	33	M30	50	12
DN200	55.5	33	M30	50	12	53.5	39	M36	60	12
DN250	63.5	36	M33	55	16	70	39	M36	60	16
DN300	66.5	36	M33	55	16	79.5	39	M36	60	20
DN350	70	39	M36	60	20	86	42	M39	65	20
DN400	76.5	42	M39	65	20	89	45	M42	65	20
DN450	83	45	M42	65	20	102	52	M48	75	20
DN500	89	45	M42	65	24	108	58	M52	80	20
DN550	95	48	M45	70	24	/	/	/	/	/
DN600	102	52	M48	75	24	68	64	M64	/	20

 

Driven by strong demand in the marine, chemical, oil and gas, and high-salinity environments sectors, 316 stainless steel flanges and fasteners are typically 10% to 20% more expensive than 304, reflecting their superior corrosion resistance and lower material costs. GNEE maintains a large inventory of 304 and 316 flanges, bolts, and nuts, with standard sizes available in 7 to 15-day lead times.

Packaging: Wooden crates or pallets with moisture-proof protection, suitable for sea or air shipment.