431 Thin hex nuts
ISO 4035ASTM A276 / ASTM A479
Limited axial space is the reason to use a 431 thin nut. Its hardenable stainless strength for loaded mechanical parts must be paired with the reduced thread engagement and the intended locking arrangement.
- MOQ
- 100PCS
- Samples · typical
- ~20 days
- Production · typical
- 25–35 days
- Heat treatment
- Annealed / hardened and tempered
EN 10204 3.1 MTC + heat-number traceability
Which standard is on your order?
Raw Material Specifications
Threads · Metric
Threads · Inch
Dimension Reference
Heat Treatment
Hardened and temperedHardening forms the load-bearing martensitic structure, then tempering adjusts hardness and toughness to the specified final condition.
What we can make in 431
Reduced-height body
Use in compact adjustment mechanisms and panel assemblies where axial clearance rules out a full-height nut. Check the required proof load against the reduced engagement rather than selecting on clearance alone.
Jam-nut arrangement
Use with a second nut to lock an adjustment on a threaded shaft or linkage. The specified nut order and tightening sequence are part of the locking arrangement, not simply two nuts tightened independently.
- Pattern
- Thin hex · Jam nut
- Key dimensions
- Thread · Across flats · Height
- Threads
- Metric · UNC · UNF
- Assembly
- Adjusters · Paired nuts
- Final condition
- Annealed · hardened and tempered
- Inspection
- Nut height · Across flats · Thread plug gauging
Manufacturing route
Small lots use machined blanks. Volume nut blanks use a forming route compatible with the alloy before machining the bore and tapping.
Heat treatment & final condition
Hardening and tempering set the final hardness and toughness. Finish dimensions are checked after heat treatment.
Finished geometry
Internal thread gauging, usable engagement and bearing-face alignment are checked after final processing.
Where 431 fits — and what matters
Industrial Machinery & Automation
Drive shafts, collars and guide pins431 thin hex nuts serve as jam or retaining nuts on drive shafts, collars and guide pins where axial space is limited. Their reduced thread engagement is part of the retention design. Alignment, operating cycles and replacement access define the working interface.
Automotive & EV Manufacturing Equipment
Fixture pins and positioning shafts431 thin hex nuts serve as jam or retaining nuts on fixture pins and positioning shafts where axial space is limited. Their reduced thread engagement is part of the retention design. Repeated tooling changes require consistent seating and repeatable assembly dimensions.
Pumps, Valves & OEM
Valve stems and pump-drive collars431 thin hex nuts serve as jam or retaining nuts on valve stems and pump-drive collars where axial space is limited. Their reduced thread engagement is part of the retention design. Repeated maintenance makes fit, engagement and access part of the component specification.
Same thin hex nut. Different material priorities.
431 material data316L
Molybdenum-bearing stainless performance in wet equipment.
- Connection priority
- Thread load in a reduced-height body
- Washdown and retained cleaner
- Cleaner concentration, rinse quality and deposits determine the exposure in covered joints. The low-carbon designation does not independently establish a fastener strength class. Include liquid retained at the short internal engagement and paired-nut faces in the exposure description.
17-4 PH
Aging-controlled strength and hardness.
- Connection priority
- Thread load in a reduced-height body
- H900 versus H1150
- The aging condition changes the balance of strength, hardness and toughness. A replacement part needs the specified H condition, especially where contact wear and shock load occur together.
Inconel 625
Solid-solution strength and resistance to aggressive process liquids.
- Connection priority
- Thread load in a reduced-height body
- Annealed or solution-annealed 625
- The delivery condition affects strength and high-temperature response. Keep the specified condition with the component’s mechanical acceptance; 718-style aging is not the strengthening route for 625. Include liquid retained at the short internal engagement and paired-nut faces in the exposure description.
From drawing to documented delivery
- 01Drawing & BOMForm, dimensions and quantity
- 02Material & formingGrade, heat and manufacturing route
- 03Final inspectionGeometry, threads and ordered tests
- 04Documents & dispatchLot records and identified packing
Order documents
- Material identity
- UNS S43100 · heat number · ordered condition
- Final-part acceptance
- Hardness and mechanical acceptance after hardening and tempering.
- Dimensional record
- Nut height · Across flats · Thread plug gauging
- Traceability
- EN 10204 3.1 material certificate · production lot · identified packing
Build your 431 thin hex nut enquiry
Questions about 431 thin hex nuts
Can a thin nut replace a regular nut at the same load?
Reduced thread engagement changes stripping capacity. Check the reduced-height nut’s material condition and the intended jam-nut arrangement instead of transferring the regular nut’s load assumption.