High-Performance Automotive Bypass Shock Absorber Tubes for Smooth Operation

Product Description

Product Description

Steel tubes for motorcycle shock absorbers

The process of manufacturing shock absorbers usually starts with selecting high-quality raw materials. The type of raw materials used can significantly affect the performance and lifespan of shock absorbers. Carbon steel seamless steel pipes and alloy seamless steel pipes are commonly used in the production of shock absorbers.These raw materials will undergo a series of processing steps. At these stages, accuracy is crucial to ensure that each component meets the precise specifications required to achieve optimal performance.

GRADE	chemical composition%
	C	Si	Mn	Cr	Ni	Mo	Gu	P	S
20#	0.17~0.23	0.17~0.37	0.35~0.65	≤0.25	≤0.30	----	≤0.20	≤0.035	≤0.035
45#	0.42~0.50	0.17~0.37	0.50~0.80	≤0.25	≤0.30	----	≤0.20	≤0.035	≤0.035
40Cr	0.37~0.44	0.17~0.37	0.50~0.80	0.80~1.10	≤0.30	≤0.1	≤0.20	≤0.030	≤0.030
40Mn2	0.37~0.44	0.17~0.37	1.40~1.80	≤0.30	≤0.30	≤0.1	≤0.20	≤0.030	≤0.030
37Mn	0.30~0.39	0.15~0.30	1.20~1.50	≤0.35	≤0.30	≤0.1	≤0.20	≤0.020	≤0.015

Equivalent Material referance:
GB	TOCT	ASTM	BS	JIS	NF	DIN
20	20	1020	050A20	S20C	XC18	C22,CK22
45	45	1045	080M46	S45C	XC45	C45,CK45
40Cr	40X	5140	41Cr4	SCR440	41Cr4/38Cr4	41Cr4/42Cr4
40Mn2	40Γ2‌	1340		SMn438	40N5	42Mn6
37Mn5		J55	EN46	NC-55E	38MS5	1.5122

Precision Seamless Steel Tubes for Motorcycle Shock Absorbers – Engineered for Performance & Durability

As a leading manufacturer with over 30 years of expertise in seamless steel tube production, Fujian Bluesky Pipe Manufacturing Co., Ltd. delivers premium motorcycle shock absorber precision seamless steel tubes that fully comply with China's industrial standard YB/T 4675-2018 and international benchmarks such as ASTM, JIS, DIN, and EN. Designed to meet the rigorous demands of motorcycle suspension systems—whether for street, off-road, or electric models—our tubes blend exceptional strength, tight dimensional control, and reliable performance to enhance ride comfort and safety.

1.Premium Material Selection: Tailored for Shock Absorber Demands

2. Precision Manufacturing: Tight Tolerances & Smooth Finishes

We utilize high-quality steel grades optimized for shock absorber applications, each engineered to withstand repeated mechanical stress, vibration, and environmental exposure:
 
20# & 45# Carbon Steel: Ideal for lightweight to mid-duty shock absorbers, offering excellent ductility (elongation rate ≥16%) and weldability. Tensile strength ranges from 410-550 MPa and 590-645Mpa, with annealing (+A) or normalizing (+N) options for reduced brittleness.
 
40Cr & 40Mn2 Alloy Steel: For heavy-duty or high-performance motorcycles (e.g., racing, off-road). Boasts tensile strength ≥780 MPa and Rockwell hardness (HRC) of 22-30, ensuring resistance to deformation under extreme loads.
 
37Mn5 Steel: A top choice for precision suspension systems, with strict impurity control (P≤0.020%, S≤0.015%) and tensile strength ≥780 MPa. Complies with YB/T 4675-2018's Non metallic inclusions requirement (≤2.5 grade per GB/T 10561-2005), guaranteeing uniform material structure.
 
All steels are smelted via electric arc furnace + secondary refining or oxygen converter + secondary refining, and processed from high-quality billets (compliant with YB/T 4149, YB/T 5221, YB/T 5222) to eliminate internal defects.

Our advanced cold-drawing and cold-rolling processes, paired with strict quality control, ensure every tube meets the exacting standards of motorcycle shock absorber assembly:
 
Dimensional Accuracy: Outer diameter (OD) ranges from 18-38mm, inner diameter (ID) tailored to your needs, with tolerances as tight as OD ±0.05mm and ID +0.039mm (for cold-worked states +C/+LC). Wall thickness options (2-5mm) feature a tolerance of ±6%, ensuring perfect fit with shock absorber components (e.g., pistons, rods).
 
Surface Quality: Inner surface roughness (Ra) ≤0.8μm and outer surface Ra ≤1.6μm (per GB/T 1031), minimizing friction between the tube and shock absorber fluid for smoother damping performance. Cold-worked tubes retain a clean, phosphate/lubricant coating (for rust protection during storage), while heat-treated tubes (+A/+SR/+N) are free of loose scale.
 
Heat Treatment Flexibility: Choose from 5 delivery states to match your assembly needs:
+C (Cold-drawn/rolled/Hard): For direct use in high-stiffness applications.
+LC (Cold-drawn/rolled/Soft): Post-heat treatment for enhanced ductility.
+SR (Stress-Relieved Annealing): Reduces residual stress to prevent long-term deformation.
+A (Annealing): Maximizes ductility for easy forming.
+N (Normalizing): Improves material uniformity for consistent performance.

OD * ID	Allowable deviation of outer diameter	Allowable deviation of inner diameter
18*16       22*20     22.5*20  24*21  39.5*36	0/+0.1	0/+0.039
24*20       24*22     30*28   32*30
26.2*18    27.2*18   28.2*22.7	±0.05	±0.05
30.2*25    31.2*24		±0.1
27.2*19    30.2*24   33.2*24   33.2*28   35.2*28   35.2*31    37.2*32     37.3*33		-0.15/-0.05
37.5*32     41.5*37		+0.05/+0.15
26.2*19     26.2*20   30.2*26   32.2*24     37.2*31   41.2*35.8		-0.25/-0.05
30.35*24     37.35*31	-0.1/0

GRADE	DELIVERY CONDITION
	+C	+LC	+SR	+A	+N	HRC
	Rm/A%	Rm/A%	Rm/Rel/A%	Rm/A%	Rm/Rel/A%
	≤
20#	550/5	520/8	520/375/12	390/21	410/245/25	----
45#	645/8	----	----	590/14	600/355/16	----
40Cr	780/10	----	----	----	----	22~30
40Mn2	780/10	----	----	----	----	22~30
37Mn	780/12	----	----	----	----	20~27

3. Rigorous Quality Inspection: Zero Compromise on Reliability

4. Wide Application: adaptation Global Motorcycle Brands

5. Customer-Centric Services: Support Your Success

Every tube undergoes a multi-step testing process to ensure compliance  and customer requirements:
 
Non-Destructive Testing: 100% full-length eddy current testing  to detect surface and near-surface defects (e.g., cracks, pits).

Mechanical Testing: Tensile tests , Rockwell hardness tests , and flattening/expansion tests  to verify strength, hardness, and ductility.

Chemical Analysis: Direct-reading spectrometer and ICP-OES testing  to confirm chemical composition accuracy.

Dimensional & Visual Checks: Each tube is measured with precision gauges for OD/ID/wall thickness, and visually inspected for surface defects (scratches ≤0.04mm deep, no cracks).

Our shock absorber tubes are compatible with leading motorcycle manufacturers and models, including:
 
Japanese Brands: Honda, Yamaha, Suzuki, Kawasaki, Yamaha (e.g., Haojue, XinDazhou Honda).

European Brands: BMW Motorrad, Ducati, KTM.

Electric Motorcycles: Customized tubes for lightweight, high-efficiency electric suspension systems.

Off-Road & Racing Bikes: Heavy-duty 40Cr/37Mn5 tubes for extreme terrain and high-speed conditions.

We understand the needs of global buyers and offer flexible solutions to streamline your supply chain:
 
Free Samples & Testing: Request free samples for lab verification  before bulk orders.

Low MOQ: Start with 1 ton per order—ideal for small-batch trials or custom projects.

Customization: Tailor OD, ID, wall thickness, length , and surface treatments to your specs.

Flexible Payment & Delivery: Accept T/T, L/C, and D/P . Fast production lead times (17-25 days for standard orders) and global shipping via sea/air.

Certifications: Backed by ISO 9001,IATF16949, ISO 14001, ISO 45001, and China's "High-Tech Enterprise" certification , ensuring consistent quality.

Partner with Bluesky: Your Trusted Supplier for Motorcycle Shock Absorber Tubes

Whether you're a motorcycle OEM, aftermarket parts distributor, or suspension system designer, our precision seamless steel tubes deliver the performance, reliability, and value you need. With a track record of supplying clients like Haojue, Schaeffler, and Toyota's tier-1 suppliers, we're committed to becoming your long-term partner in the global market.

We offer a one-stop processing service, capable of directly machining steel tubes into shock absorber bodies for you, whether it's a motorcycle front fork shock absorber or an off-road bypass shock absorber.

Calibration of motorcycle shock absorber tube components

We are conducting high-precision point calibration for motorcycle shock absorber tube components, ultimately controlling their straightness accuracy within 0.05mm

FAQ

Q: Are you trading company or manufacturer?
A: We are professional manufacturer for steel pipes,and our company also is a very professional and technical foreign trade company for steel products. We have more export experience with competitive price and best after-sales service. Apart from this,we can provide a wide range of steel products to meet the requirement of customer.

Q:Will you delivery the goods on time?
A: Yes,we promise to provide best quality products and delivery on time no matter if the price change lot or not. Honesty is our company's tenet.

Q: Do you provide samples ? is it free or extra?
A: The sample could can provide for customer with free,but the freight will be covered by customer account. The sample freight will be returned to customer account after we cooperate.

Q: How can I get your quotation as soon as possible?
A: The email and fax will be checked within 24 hours,meanwhile,Wechat and WhatsApp will be online in 24 hours. Please send us your requirement and order information,specification(Steel grade,size,quantity,destination port),we will work out a best price soon.

Q: Do you have any certifications?
A: Yes,that's what we guarantee to our clients. we have IS09000,IATF16949 certinicate,ISO 14001 certificates etc.Our products are of high quality and we have professional engineers and development team.

Q: What is your terms of payment?
A:Payment<=1000USD, 100% in advance. Payment>=1000USD, 30% T/T in advance ,balance before shipmenit or paid against copy of B/L within 5 working days. 100% Irrevocable L/C at sight is favorable payment term as well.

Q: Do you accept the third party inspection?
A: Yes absolutely we accept.

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