What is the difference between A2 and A4 stainless steel bolts?

A2 (304) is ideal for standard outdoor and industrial use, while A4 (316) contains molybdenum, offering higher corrosion resistance for marine, chemical, and salt-spray environments.

Will stainless steel bolts rust over time?

Under severe chemical or chloride exposure, A2 may develop slight surface corrosion. A4/316 performs better in harsh environments. We also offer passivation treatment for enhanced protection.

High Quality Stainless Steel Carriage Bolt Coach Bolt Mushroom Head Square Neck Bolt

Name: High Quality Stainless Steel Carriage Bolt Coach Bolt Mushroom Head Square Neck Bolt
Brand: Ningbo Mianxuan Import &Export Co., Ltd.
SKU: 1983145981

Zhejiang, ChinaNingbo Mianxuan Import &Export Co., Ltd.

US$0.10

5,000-19,999 Pieces

US$0.07

20,000-49,999 Pieces

US$0.05

50,000+ Pieces

Sample price:US$0.00/piece.Request sample

Product profile

Customization

Available

Material

Stainless Steel

Type

Round Head

Model NO.

DIN603

Connection

Common Bolt

Head Style

Round

Standard

DIN, ANSI, GB, JIS, BSW, GOST, ISO

Grade

A2, A4

Application

Machinery, Chemical Industry, Environmental, Building

Finish

Polishing

Quality

100% Tested

Price

Factory Price

Delivery

15-30 Days

Surface

Plain, Zinc Plated (Blue, White, Black, Yellow)

Package

Standard Package or Customer's Packing

Box

Customer's Brand Box/Plain Box

MOQ

Can Be Negotiated

Shipment

by Sea / Truck / Plane / Express

Exterior Finish

Passivation

Sample

Available

Customized

Available

Service

One-Stop Service

Online Sales

24 Hours Online

OEM/ODM

Available

Head

Round

Transport Package

Bulk Packaging, Small Box(Glue Box, Color Box)

Specification

M5-M20

Trademark

Mianxuan, Customized

Origin

Ningbo Zhejiang

Production Capacity

30000tons/Year

Key features

Multi-Grade Stainless Steel: Supply A2/A4 grades including 304 and 316 for various corrosion resistance needs.

Custom OEM/ODM Service: Produce according to drawings, samples, or specific head/drive combinations.

Strict Quality Control: Test torque, hardness, thread precision, and salt spray per ISO 9001 standards.

Free Sample Availability: Provide free or low-cost samples for quality and dimension confirmation.

Wide Standard Compliance: Comply with DIN, ISO, ANSI, JIS, GB, and other international standards.

Flexible Packaging Options: Offer standard packaging or customer's brand box/plain box customization.

Fast Delivery Time: Lead time of 15-30 days, with off-season delivery within 15 workdays.

One-Stop Service: Provide comprehensive support including online sales and technical assistance.

Company profile

High Repeat Buyers ChoiceYears of Export ExperienceR&D CapabilitiesODM Services

Ningbo Mianxuan Import &Export Co., Ltd.

Zhejiang, China

Business Type: Manufacturer/FactoryExport Year: 2014-07-01Nearest Port: Ningbo, Zhapu, ShanghaiAverage Response Time: ≤3.32hTerms of Payment: LC, T/T, Western UnionInternational Commercial Terms(Incoterms): FOB, EXW, CFR, CIF

AI-Powered supplier vetting

SummaryNingbo Mianxuan Import & Export Co., Ltd. is identified as a China-based manufacturer/factory in Zhejiang, offering vehicle parts, CNC machining parts, metal stamping, castings, fasteners, and related products. It reports TS 16949 and ISO 9001 certifications, more than 10 production lines, 6–10 quality-control staff, and shipment inspection reports with material certificates. The supplier provides 3D software design, ODM, and several customization options, but reports no new products in the past year, no SDK, and no OEM service for popular brands. Service infrastructure is limited: no in-stock capability, overseas warehouse, or overseas showroom, while service assessment, complaint handling, and corrective-action procedures lack written records. Financial information is limited to year labels without substantive performance values. No customer cases are provided.

Supplier typeThe supplier is explicitly classified as a Manufacturer/Factory and a limited company based in Ningbo, Zhejiang, China. Its stated product scope covers vehicle parts, CNC machining parts, metal stamping, castings, fasteners, plastic parts, and rubber parts, supporting classification as a diversified manufacturing supplier.

CertificationsThe supplier reports holding TS 16949 and ISO 9001 management-system certifications. It also states that each shipment will include an inspection report with a corresponding material certificate, indicating documented quality-related deliverables.

After-Sales capabilityThe supplier reports no in-stock service capability, overseas warehouse, or overseas showroom. It also has no written procedures or records for service assessment, complaint handling, or corrective and preventive actions, while contract status for manufacturing capacity is unknown.

Production capacityThe supplier operates more than 10 production lines, has 6–10 quality-control staff, and offers a broad metal, machining, casting, plastic, rubber, and vehicle-parts scope. It lists Ningbo and Shanghai ports, 21 qualified suppliers for service capability, and a one-month off-season lead time; peak-season lead-time data is inconsistently stated, limiting a complete capacity assessment.

Customization capabilityThe supplier explicitly offers customization from samples, customization from designs, full customization, and minor customization, in addition to ODM services. These options directly support customized product development, although no evidence is provided for SDK-based development or OEM service for popular brands.

Product Q&A

Q:What thread standards do you follow?

Our screws comply with DIN, ISO, ANSI, and JIS standards, and can also be customized according to customer drawings.

Q:What stainless steel grades do you supply for bolts?

We supply multiple grades including A2-70, A2-80, A4-70, A4-80, 304, 316, and 410SS, suitable for different mechanical strength and corrosion-resistance requirements.

Q:Do you provide samples before mass production?

Yes, we offer free or low-cost samples for quality and dimension confirmation prior to order.

Q:How do you control product quality?

Every batch is tested for torque, hardness, thread precision, and salt spray corrosion resistance, following ISO 9001 quality system standards.

Q:Do you offer OEM or customized production?

Yes. We can produce screws according to samples, technical drawings, or specific drive/head combinations, and offer custom packaging and labeling.