UNS S31009

Stainless Steel 310H Hex socket countersunk screws

ISO 10642

Flush seating puts the load into the conical head of a Stainless Steel 310H countersunk screw. Controlled-carbon stainless performance for sustained hot loading is combined with a matching head angle and acceptance of the reduced head section.

MOQ
100PCS
Samples · typical
~20 days
Production · typical
25–35 days
Heat treatment
Solution annealed

EN 10204 3.1 MTC + heat-number traceability

Upload drawing
Other alloys800HT718A-286310S

Which standard is on your order?

Threads · Metric

Threads · Inch

Dimension Reference

Heat Treatment

Solution annealed

Solution annealing and rapid cooling retain alloying elements in solution and restore the specified corrosion-resistant condition.

What we can make in Stainless Steel 310H

Countersunk head seating angle

Head angle & seating

90° metric and 82° inch heads need matching countersinks. Head diameter and recess depth control whether the screw sits flush.

Socket recess and overall length including head

Socket & overall length

Specify overall length including the head. Socket size and depth govern key engagement, especially in shallow head sections.

Reduced head section between socket and conical seat

Reduced head loadability

ISO 10642 identifies reduced loadability from the countersunk head and socket geometry. For Inconel 718 or A-286, assess head capacity and seating contact alongside the specified material strength and assembly preload.

Drive
Internal hex socket
Head angle
90° metric · 82° inch
Length basis
Overall, including head
Threads
Metric · UNC · UNF · UNJ
Final condition
Solution annealed
Inspection
Head angle & diameter · Socket size & depth · Overall length · Thread gauges

Manufacturing route

CNC machining suits samples and small lots. Cold heading or hot forging is selected for volume production according to alloy formability, head section and size.

Heat treatment & final condition

The ordered annealed or solution-treated state is retained in the lot record; forming and machining do not replace the specified thermal condition.

Finished geometry

Head angle, socket depth and the head-to-shank transition are inspected with the thread; the reduced head section remains part of finished-part acceptance.

Where 310H fits — and what matters

Heat-treatment workshop with horizontal furnaces, green pipes and a blue motor

Furnaces & Heat Treatment

Furnace shields and casing panels

Stainless Steel 310H hex socket countersunk screws secure furnace shields and casing panels with the head below or flush with the surface, leaving clearance for neighbouring moving parts or removable covers. Hot dwell, thermal expansion and repeated furnace cycles set the working load.

90° / 82° seat · head section · socket engagement
Furnaces & Heat Treatment fasteners
Technician inspecting blade rows beneath a large turbine rotor

Power & Turbines

Hot-duct shields and thermal baffles

Stainless Steel 310H hex socket countersunk screws secure hot-duct shields and thermal baffles with the head below or flush with the surface, leaving clearance for neighbouring moving parts or removable covers. Hot dwell and start-stop expansion act on the supported or moving component.

90° / 82° seat · head section · socket engagement
Power & Turbines fasteners
Silver distillation columns with access ladders and yellow service platforms

Chemical Processing

Process-heater shields and baffles

Stainless Steel 310H hex socket countersunk screws secure process-heater shields and baffles with the head below or flush with the surface, leaving clearance for neighbouring moving parts or removable covers. These parts work in the heated equipment zone, where sustained loading and thermal expansion govern their section and clearance.

90° / 82° seat · head section · socket engagement
Chemical Processing fasteners

Same hex socket countersunk screw. Different material priorities.

Stainless Steel 310H material data
UNS N08811

Incoloy 800HT

Tightly controlled carbon and Al + Ti for creep duty.

Connection priority
Head-bearing stress in the reduced countersunk section
N08811 material control
800HT tightens the 800-family chemistry around creep performance. Its solution-treated, coarse-grain condition and N08811 identity should remain linked through forming and final acceptance. At the conical seat and recessed socket, the relevant metal temperature can differ from the process or furnace set point.
Incoloy 800HT hex socket countersunk screws
UNS N07718

Inconel 718

Precipitation-hardened strength for compact, highly loaded connections.

Connection priority
Head-bearing stress in the reduced countersunk section
Strength after aging
Machine-stock properties and final aged properties describe different states. The final heat-treatment lot and mechanical results establish the strength available in the installed part. At the conical seat and recessed socket, the relevant metal temperature can differ from the process or furnace set point.
Inconel 718 hex socket countersunk screws
UNS S66286

A-286

Aged iron–nickel alloy strength for hot bolting.

Connection priority
Head-bearing stress in the reduced countersunk section
Grade 660 class
An ASTM A453 Grade 660 order includes its class and corresponding processing requirements. The alloy name A-286 alone does not identify that acceptance condition. At the conical seat and recessed socket, the relevant metal temperature can differ from the process or furnace set point.
A-286 hex socket countersunk screws

From drawing to documented delivery

Heat treatment
Heat treatment
CNC machining
CNC machining
Rockwell hardness testing
Rockwell hardness testing
Wooden-crate packing
Wooden-crate packing
  1. 01Drawing & BOMForm, dimensions and quantity
  2. 02Material & formingGrade, heat and manufacturing route
  3. 03Final inspectionGeometry, threads and ordered tests
  4. 04Documents & dispatchLot records and identified packing

Order documents

Material identity
UNS S31009 · heat number · ordered condition
Final-part acceptance
Grade chemistry, supplied condition and ordered mechanical requirements.
Dimensional record
Head angle & diameter · Socket size & depth · Overall length · Thread gauges
Traceability
EN 10204 3.1 material certificate · production lot · identified packing

Build your 310H hex socket countersunk screw enquiry

QUOTE LIST ITEMStainless Steel 310H hex socket countersunk screws; UNS S31009; 90° metric countersunk head

Questions about 310H hex socket countersunk screws

Does a high-strength alloy remove countersunk-head loadability limits?

The conical head and socket still reduce the available section. Head-bearing stress, countersink contact and housing thread engagement need assessment alongside the final alloy strength.

Technical references & photo credits