Five key Questions to Ask when Purchasing Hot-rolled Stainless Steel
1.What is the thickness tolerance range?
The thickness of hot-rolled stainless steel directly affects the processing accuracy and cost control, and the tolerances under different standards vary greatly
Standard
Typical thickness tolerance (mm)
Applicable scenarios
GB
±0.15~±0.3
General use
ASTM
±0.1~±0.2
Precision machining
JIS
±0.05~±0.15
High-end equipment
Tips for avoiding pitfalls
Clear requirements: The requirements for stamping parts are strict (within ±0.1mm), while for structural parts, the requirements can be relaxed (±0.2mm).
Contract note: Clearly state "Acceptance in accordance with ASTM A480" or JIS G4303 standard to avoid ambiguous expression.
2. Should the surface treatment be 2B, No.1 or HRAP?
Different surface conditions determine the subsequent processing methods and the final appearance:
Surface type
Features
Applicable scenarios
2B
Bright annealing after cold rolling, smooth and uniform
Home appliances, decoration
No.1
Pickling after hot rolling, slightly rough
Industrial equipment, structural parts
HRAP
Only shot blasting after hot rolling, retaining oxide scale
Low-cost rough processing
Tips for avoiding pitfalls
For welded parts, No.1 is preferred (the oxide scale has been removed).
Use 2B directly (no polishing required);
For those with a limited budget and requiring secondary processing, HRAP is an option.
3. What is MOQ (Minimum Order Quantity)?
Hot-rolled stainless steel is usually sold by coil or ton, and MOQ restrictions directly affect procurement costs:
Large steel mills: Usually with a minimum order of 20 tons (such as Taiyuan Iron & Steel, POSCO);
Trader: The minimum order quantity may be 5 tons (but the unit price is 10 to 15% higher).
Special specifications (such as ultra-thin/ultra-thick) : possibly over 50 tons.
Tips for avoiding pitfalls
Small-batch trial orders? Find a spot inventory provider to avoid being bound in quantity.
Long-term demand? Negotiate tiered prices (such as a 5% discount for orders over 30 tons).
4. Does the material provide a certificate of quality assurance (MTC)?
MTC (Material Test Certificate) is the core guarantee of quality and must include:
Chemical composition (such as Ni≥8% in 304, Mo≥2% in 316);
Mechanical properties (tensile strength, elongation);
Heat treatment status (whether it is solution treatment).
High-risk signal
The supplier refused to provide MTC.
MTC does not have third-party inspection stamps (such as SGS, BV).
5. How are the delivery cycle and logistics responsibilities divided?
Hot-rolled stainless steel projects are often halted due to delayed production scheduling or transportation issues.
Domestic delivery: Confirm whether freight is included (EXW/FOB terms);
Imported materials: Inquire about the stability of the shipping schedule (Southeast Asian supplies are often delayed);
During special periods (such as when nickel prices soar), the contract should specify a clause for compensation for breach of contract.