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+86 13143444311
Email：sst@szsst88.com
Fax：+0086-755-27322278
Address：Building 9, First Industrial Zone, Tantou Industrial City, Songgang Street, Baoan District, Shenzhen 518105, Guangdong, China
Type:Stainless Steel Socket Head Cap Screws
Materials:Stainless Steel
Surface treatment:Plain
Head Type:Cap Head
Drive:Hexagon socket (Allen)
Thread:Self-tapping, half thread
Point:Flat, blunt
Forming:Single Die Heading
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M14
Number:457
We make stainless steel socket head cap screws in passivated A2, with a cylindrical head, hexagon socket, half thread and flat self-tapping point, quoting them from M1 to M14. Socket depth, thread form, point and grade come from your drawing, and the first article is driven at your joint torque.
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ISO 9001:2015 · Manufacturing since 1998 · 8,678+ customers · 89 countries and regions
Made to order – there is no stock catalogue. Each part is produced to your drawing, and production starts after drawing review and first-article approval.
These stainless steel socket head cap screws have a cylindrical head with a hexagon socket, a half thread and a flat self-tapping point, made in passivated A2 stainless and quoted from M1 to M14 with Number 457.
Socket cap head. A flat-topped cylinder with an internal hexagon and a flat bearing face, seated in a counterbore.
Self-tapping thread. A thread that forms its own thread in the material it enters, so no tapped hole is needed at the far end.
Half thread. The plain shank runs through the front parts and only the last section forms a thread.
Passivated stainless. A2 grade, uncoated, so the socket and the thread are as made.
Stainless steel socket head cap screws are used where a socket drive and a corrosion-resistant body are both needed and the far part cannot be tapped: washdown machinery, outdoor fittings and food or laboratory equipment.
The head, the drive and the thread are chosen together, because each one changes how the part is driven.
A stainless steel socket head cap screw of this type carries three decisions in one part. The stainless body removes the coating question, so the socket and the thread are the size the drawing says at every batch. The socket is the drive: forming a thread takes torque, and a hexagon delivers it without cam-out. And the flat self-tapping point lets the screw make its own thread in a soft far part rather than run into a tapped hole.
In stainless steel socket head cap screws the stainless part is more than a finish choice. On a self-tapping screw the thread is formed by the screw working the material, and a coating thick enough to protect the thread would blunt the point and round the crest; plain stainless has neither problem, and the alloy itself resists corrosion after the thread has been cut into the part.
On stainless steel socket head cap screws the socket is what makes the forming practical. The torque needed to form a thread is higher than the torque needed to run into a tapped hole, and a cross recess at that load will climb out; a hexagon holds, and the key can be re-applied as often as the joint needs. The cost is that the socket is only as good as the key: a worn key rounds the corners at the torque the thread needs.
On stainless steel socket head cap screws the half thread keeps the front of the joint clean. The plain shank passes the clearance holes and the thread forms only at the far end, so the parts in between are not threaded on the way through — which on a joint that has to come apart matters as much as the holding force.
On stainless steel socket head cap screws the counterbore completes the joint. A cap head sits below the surface on a machined face, so the fixing is out of the way while the head still bears on its full diameter; a pocket that is too shallow holds the head off and the screw then sits on its shank.
The recorded range is M1 to M14, with lengths made to the drawing. Custom lengths up to 2,000 mm are subject to DFM review after drawing submission. For stainless steel socket head cap screws the quotation carries head diameter and height, socket size and depth, thread length, point and the grade.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Socket cap head | Head diameter, height and face flatness |
| Socket | Internal hexagon | Across flats, depth and corners |
| Shank | Plain section through the joint | Diameter and length |
| Thread | Self-tapping, half thread | Thread form, length and crest condition |
| Point | Flat, blunt | Point diameter and squareness |
| Material | A2 stainless | Grade and heat number on the certificate |
| Finish | Passivated | Surface condition and film |
Socket depth and head height are quoted together, because the socket is what limits the torque and the torque is what forms the thread.
Threaded length is quoted from the point and plain length from the head. On stainless the plain section is what runs in the clearance holes, and its diameter decides whether the joint slides together or binds.
Three features define the part: the socket, the stainless body and the forming thread. The first delivers the torque, the second keeps the geometry as made, and the third removes the tapped hole.
| Feature | What it gives | What it costs |
|---|---|---|
| Socket drive | Torque without cam-out | Needs the exact key size |
| Stainless body | No coating in socket or thread | Galls dry; softer than steel |
| Self-tapping thread | No tapped hole in the far part | Pilot hole must be right |
| Cap head face | Full ring of contact in a counterbore | Counterbore must be flat and deep enough |
| Flat point | Starts in a pilot without piercing | Needs a drilled hole to locate |
On stainless steel socket head cap screws the body is the reason the part is chosen over its plated equivalent. A coated screw loses its coating in the socket first, and a socket that has lost its coating is a socket that will round sooner; passivation leaves the hexagon exactly as cut.
The cost is galling. Stainless against stainless, or stainless against a stainless nut, can seize when driven dry under pressure, and a seized self-tapping screw in a soft part cannot be extracted without damage.
The recorded finish is passivation with no coating on A2 stainless. On a socket head that is the right finish for a simple reason: the socket is the drive, and nothing is added inside it. A coated socket is a socket one size smaller than the drawing.
| Option | How it protects | Effect on socket and thread | Typical use |
|---|---|---|---|
| A2 stainless, passivated | Passive chromium oxide film | Socket and thread as made | Wet and outdoor assemblies |
| A4 stainless, passivated | Passive film with molybdenum | Socket and thread as made | Marine and medical |
| Steel, nickel plated | Barrier deposit, bright | Socket narrowed; re-checked | Visible indoor machine work |
| Steel, zinc plated | Sacrificial zinc | Thin build; socket re-checked | General indoor work |
| Steel, black oxide | Conversion film, oiled | No measurable build | Internal mechanisms |
Where the joint is wet, A4 is the grade and the socket is the reason: a rusted socket cannot be re-entered cleanly, and a cap head offers nothing else to grip.
Where the joint is dry, a plated steel screw does the same work for less; the stainless version is chosen for the environment rather than for the strength.
Three assemblies where these screws are the fixing:
| Where it sits | The screw holds a cover or a bracket on equipment that is cleaned, where the socket has to stay usable through the cleaning regime. |
| When it goes wrong | A plated screw rusts in the socket, and the cover cannot be removed. |
| Why it happens | The joint is wet, it is serviced, and the drive is a key. |
| What we control | Grade confirmed; first article assembled and released. |
| Where it sits | The screw forms its own thread in an aluminium or plastic fitting on equipment that lives outdoors. |
| When it goes wrong | A coated screw blunts its point during forming, and the thread does not start. |
| Why it happens | The joint is outside, the far part is soft, and no tapped hole exists. |
| What we control | Pilot hole agreed; first article driven into a sample. |
| Where it sits | The screw fixes a panel where the material must be stainless and the head must sit in a counterbore. |
| When it goes wrong | A steel screw rusts at the socket, and a coating flake contaminates the product. |
| Why it happens | The joint is hygienic, it is cleaned, and the fastening is inspected. |
| What we control | Grade and passivation confirmed; first article fitted. |
Four reasons that matter on a stainless socket screw, each tied to what the drawing has to prove:
|
Socket and point agreed
Socket depth, thread form, point and grade are agreed as a set, because on stainless steel socket head cap screws the drive has to form the thread. Basis: Socket and point agreed. |
Headed, threaded, passivated in one route
The cap head and hexagon are formed, the self-tapping thread rolled and the flat point cut before passivation. Basis: One route from wire to passivated screw. |
|
Socket and thread checked
The socket is checked for depth and the thread gauged, because both are interfaces the customer feels. Basis: Socket and thread checked. |
Driving torque recorded
The driving torque into the customer material is recorded, so a repeat order does not stall or seize at assembly. Basis: Driving torque recorded. |
Shi Shi Tong forms these screws on single-die headers that form the cylinder and cut the hexagon, rolls the self-tapping thread, cuts the flat point and passivates the parts. The first part of every run is measured on head diameter and height, socket depth, thread and point before the batch continues.
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Stainless is less forgiving in the thread roll than steel. The alloy work-hardens as it forms, so the thread is rolled in one pass with sharp tooling; a roll that rubs leaves a torn crest that gauges at the ends and binds in the middle, which on a self-tapping screw shows up as a thread that will not start.
What decides whether these screws pass is the socket, the thread form, the point and the grade. The inspection agreement covers those, and the criteria come from the drawing.
Head and point on the projector |
Thread form checked |
Hardness checked on the wire |
Salt-spray testing of the grade |
The socket is checked for across flats and depth, the thread for form and length, and the point for diameter and squareness. The head is measured for diameter, height and face flatness, and the grade is confirmed on the mill certificate.
The first article is driven into the customer material with the production key and the driving torque recorded. A screw that measures correctly and rounds its socket at that torque is a part that fails, and only the drive shows it.
Every shipment of stainless steel socket head cap screws is traceable to the wire it was made from and to the passivation batch. The grade and heat number are recorded on the material certificate supplied with the parts, and the inspection records follow the criteria agreed on the drawing.
ISO 9001:2015 |
RoHS test report |
Registered trademark |
Patent: security screw and driver |
With each batch we supply the material certificate, the inspection record for the criteria on the drawing and, where it is listed, the third-party report for the grade. The documents carry the drawing revision and the batch number, so a repeat order keeps the same socket and thread form.
More than 8,678 customers in 89 countries and regions have ordered from Shi Shi Tong; 87% of orders come from repeat customers and 56% through referrals. Most projects follow the same route: drawing review, first-article approval, then batches checked against that sample. On these screws the first article is driven into the customer material at the joint torque, because the formed thread is what the joint uses. Buyers visit during the process to review samples.
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8,678+
customers served
|
87%
of orders from repeat customers
|
56%
of orders through referrals
|
89
countries and regions shipped to
|
Buyers and quality engineers visit for sample review, process discussion and supplier audits; the visit is arranged around production so the headers and the passivation line can be seen on the day the parts run.
Customer group visit – sample review |
Customer group visit – process discussion |
Customer group visit – factory tour |
Customer visit – project kick-off |
Danish customer – drawing review |
Industry exhibition – meeting customers |
Forming a thread takes torque, and a hexagon delivers it without cam-out; a cross would climb out and damage the head.
Yes. The flat point starts in a drilled pilot and forms the thread; without one it will not start cleanly.
No coating in the socket or on the point, so the drive and the thread stay at drawing size, and the part resists corrosion after forming.
Stainless on stainless can gall when driven dry. Use a lubricant at assembly or a dissimilar grade.
Enough depth for the head and a flat face, so the head seats on its bearing face.
Head diameter and height, socket size and depth, thread form and length, point, and the grade.
How a stainless socket screw project runs from drawing to repeat delivery:
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1
Send the drawing and the material it enters
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→ |
2
Socket, thread form and pilot hole agreed
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→ |
3
First article driven at the joint torque
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→ |
4
Batch production and repeat orders
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Each step is confirmed with you before the next one starts; the drawing revision from the first article is what repeat orders are checked against.
For a quotation, send the drawing with the head diameter and height, socket size and depth, thread form and length, point, and the grade.
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Head diameter
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Socket size
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Thread form
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Point
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Overall length
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Grade
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Sending a drawing? The form below does not take attachments. Email the PDF, DXF or STEP file to sst@szsst88.com with the part name and quantity in the subject line – the drawing is reviewed and a quotation follows.
+86 13143444311
sst@szsst88.com
