Mechanical properties, corrosion behaviour and the full dimensional range for this grade.
A4 Stainless Steel Solderable SMT Nuts are supplied to ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80. Corrosion behaviour is superior, including marine and chloride environments, the material is largely non-magnetic, and the usable service range is approx. -200 °C to +400 °C, subject to the property class and the joint. In practice this grade is specified for marine, coastal and chemical applications.
Grade
ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80
Corrosion resistance
Superior, including marine and chloride environments
Magnetic response
Largely non-magnetic
Service temperature
approx. -200 °C to +400 °C, subject to the property class and the joint
Property values are typical for the grade. Certified mechanical test data is available on request for production orders.
Hidden Deck Fasteners Sourcing: Manufacturing, Types & Material Compatibility
For solderable smt nuts in A4 Stainless Steel, the controlling selection factors are corrosion exposure, strength requirement and service temperature. The grade data for A4 Stainless Steel (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80) is summarized below together with every size supplied.
Why Choose A4 Stainless Steel for Solderable SMT Nuts
Specified for marine, coastal and chemical applications. For solderable smt nuts, this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
Grade designation
ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80
Magnetic response
Largely non-magnetic
Service temperature
approx. -200 °C to +400 °C, subject to the property class and the joint
Corrosion characteristic
Superior, including marine and chloride environments
Corrosion Behavior in Service
A4 (316) adds 2–3% molybdenum to the A2 (304) composition, which dramatically improves resistance to chloride-pitting corrosion. For Solderable SMT Nuts in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Galvanic & Galling Considerations
Two important notes for stainless solderable smt nuts: (1) stainless can gall on stainless threads under load — use a thread lubricant or anti-galling compound, especially for M6 and below; (2) when joined to aluminum or galvanized steel, stainless can drive galvanic corrosion of the less-noble metal in wet service — isolate with a coating or sleeve where appropriate.
Using Stainless Fasteners in Aluminum
The galvanic couple here runs the wrong way: aluminum is the less noble metal, so it corrodes and the fastener does not. What governs the rate is the ratio of areas — a large anode and a small cathode is a tolerable combination, the reverse concentrates the attack into thin material around the hole. An isolating washer plus sealant breaks the circuit; where that is impractical, match the fastener to the substrate.
Sizes of Solderable SMT Nuts Available in A4 Stainless Steel
Thread size
Material
Supply
Board installation
Adhesive spot
M2
tinned steel
taped and reeled
solder into plated-through or non-plated hole
with or without
M2.5
tinned steel
taped and reeled
solder into plated-through or non-plated hole
with or without
M3
tinned steel
taped and reeled
solder into plated-through or non-plated hole
with or without
M4
tinned steel
taped and reeled
solder into plated-through or non-plated hole
with or without
M5
tinned steel
taped and reeled
solder into plated-through or non-plated hole
with or without
Technical Drawing
Customize the parameters below — every spec field is editable, and the drawing redraws to match the values you choose. Changing the size will snap the other fields to that size's standard values; you can then override any individual value.
Sends the selected values to the quote form below.
Request a Quote
The form below follows the current technical drawing configuration. Change the drawing values above and the request details update automatically.
Dimensions & Specifications (Trade series (solderable SMT nuts))
Thread size
Material
Supply
Board installation
Adhesive spot
M2
tinned steel
taped and reeled
solder into plated-through or non-plated hole
with or without
M2.5
tinned steel
taped and reeled
solder into plated-through or non-plated hole
with or without
M3
tinned steel
taped and reeled
solder into plated-through or non-plated hole
with or without
M4
tinned steel
taped and reeled
solder into plated-through or non-plated hole
with or without
M5
tinned steel
taped and reeled
solder into plated-through or non-plated hole
with or without
Materials & Grades
Select a material class to see the grades we supply it in. Each designation is listed with its ISO/EN, AISI/SAE, JIS and GB equivalents.
Control electronicsM2–M5 threads secure shields and board-mounted brackets.
Instrument modulesOptional adhesive spots help hold the part during soldering.
Machine building & OEMThe clamping counter-face on studs and bolts throughout an assembly.
Steel fabricationBolted structural and frame connections.
Typical applications
soldering a fine threaded nut into a plated or non-plated board hole
selecting M2 through M5 for the mating screw
using taped-and-reeled placement in production
choosing with or without an adhesive spot
joints re-torqued at a service interval
completing a bolted joint on a stud, rod or bolt
Service conditions to specify against
Marine and coastal
Available in A4 (316) stainless for chloride exposure — coastal structures, pool halls, water treatment and deck hardware, where A2 will eventually pit.
High load
Supplied in ISO 898-1 property classes, so the joint can be designed to a stated proof load and tightened to a calculated torque rather than by feel.
Match the class
A nut below the bolt property class strips before the bolt reaches its own limit — pair class 8 nuts with 8.8 bolts, class 10 with 10.9.
Where to use something else
Do not size the nut from the screw alone; the board hole, solder land and reflow process must accept the part.
This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided.
01
Cold heading
Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail.
Head dimensions and under-head radius checked at set-up and per shift.
02
Thread rolling
Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch.
Go / no-go ring gauges to ISO 965 tolerance class 6g.
03
Heat treatment
Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it.
Core hardness and tensile tested per lot to ISO 898-1.
04
Surface treatment
Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list.
Coating thickness and neutral salt spray hours to ISO 9227.
Frequently Asked Questions
What's the service temperature limit for A4 Stainless Steel?
The practical service range is approx. -200 °C to +400 °C, subject to the property class and the joint.
Can A4 Stainless Steel replace plated alloy steel structurally?
Only at the standard strength classes — A2-70 / A4-80 are roughly equivalent to class 7 steel; A4-100 reaches class 8.8. For class 10.9 or 12.9 strength, plated alloy steel is required.
Are A4 Stainless Steel Solderable SMT Nuts magnetic?
A4 Stainless Steel Solderable SMT Nuts are largely non-magnetic.
What corrosion resistance do A4 Stainless Steel Solderable SMT Nuts offer?
A4 Stainless Steel Solderable SMT Nuts provide superior, including marine and chloride environments with a service range of approx. -200 °C to +400 °C, subject to the property class and the joint.
How do I request a quotation?
Use the technical drawing on this page to pick the exact configuration, then submit it with the quote form. We respond within one business day.
Need a fastener quote or a spec sheet?Message our engineers on WhatsApp — send a drawing or DIN number and get pricing back fast.Start WhatsApp Chat →
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