By EC Fastener | Published June 4, 2026 | 4 min read
Read Part1 first：Basic Grade & Parameter Comparison
Table of Contents
Key Factors for Material Selection
Industry Application Recommendations
Functional Coating & Bi-Metal Technology
QC Tips for Global Buyers
Frequently Asked Questions
1. Key Factors in Fastener Material Selection
1.1 Environment Exposure
Core judging standard: distance from coastline, chemical erosion, treated timber contact. Within 5km coastline prefer SS316; inland regular outdoor choose SS304.
1.2 Mechanical Demand
Shear load → timber connection; tensile load → foundation anchor; drill capacity → metal roof self-drilling screw.
1.3 Substrate Matching
Stainless & carbon steel contact causes galvanic corrosion; adopt insulation washer or bi-metal screw.
1.4 Working Temperature
304/316 stable below 870℃; SS410 turns brittle under -20℃, cryogenic projects use SS316.
1.5 Full Lifecycle Cost
316 higher initial cost but 2~3x service life in corrosive environment, saving later replacement expense.
2. Application-Specific Recommendations
Outdoor Deck & Timber: Inland→SS304; Coastal/Pool→SS316
Marine & Seawall Construction: Fixed on SS316
Petrochemical Industry: SS316 high-strength bolts complying with A193 B8M
Solar Mounting: General SS304, coastal upgrade SS316, bi-metal drill screw for steel base
Metal Roof Cladding: Bi-metal screw (304/316 body + 410 drill tip)
3. Beyond Raw Material: Coating & Bi-Metal
RXB Coating: Carbon steel fastener with ≥1000h salt spray test, cost-saving substitute for partial stainless projects.
Bi-Metal Screw: Friction welded carbon steel drill tip + stainless shank, combines drilling ability and anti-corrosion, mainstream for roofing construction.
4. Quality Assurance Tips for International Buyers
Ask EN10204 3.1 MTC material certificate for batch composition
Third-party lab test report: tensile, hardness, salt spray test
Dimension inspection per DIN/ISO/ASME standard before bulk order
EC Fastener supports full batch tracking, in-house salt spray & torque test, ISO & CE certified.
5. Frequently Asked Questions
Q1: SS304 vs SS316?
316 adds molybdenum for superior salt resistance, coastal mandatory option.
Q2: Can SS410 use outdoor alone?
Not suggested; need RXB coating or bi-metal structure.
Q3: Best grade for solar fastener?
Inland SS304, coastal SS316, bi-metal drill screw preferred.
Q4: How to verify supplier quality?
Check MTC, third-party test report & factory audit.
Contact Us for Custom Material Suggestion
Email: info@ecindustry.com
Website: www.ecindustry.com