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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:Long Thread Screw Stainless Steel Hex Washer Head
Materials:Stainless Steel
Surface treatment:Plain
Head Type:Hex Washer Head
Drive:External hex
Thread:Machine thread, half thread
Point:Blunt
Forming:Multi-station heading
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M14
Number:001
We make long stainless screws in passivated A2 with a hex washer head, a half thread and a long plain shank, quoting them from M1 to M14. Flange diameter, across flats, both lengths, shank diameter and grade come from your drawing, and the first article is assembled in your joint.
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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.
Long stainless screws are machine screws whose length carries them through a spacer, a stack or a deep frame before the thread engages. This one has a hex washer head, a half thread and a passivated A2 stainless body, quoted from M1 to M14 with Number 001.
Hex washer head. Six flats with an integral flange underneath, so the clamp is spread without a separate washer.
Half thread. The plain shank runs through the joint and the thread engages only at the far end.
Long body. A shank long enough to reach through the assembly and set the distance between its parts.
Passivated stainless. A2 grade, uncoated, so the flange face, the flats and the thread are as made.
Long stainless screws are the answer when a joint has to span a gap, be cleaned or rained on, and be opened without losing a washer. The stainless body removes the coating from the rubbed surfaces, the flange removes the loose part, and the half thread keeps the span clamped rather than threaded.
On long stainless screws the head is often the only part that touches the outside of the assembly, and it is often in a place where a loose washer would be lost the first time the joint is opened. A hex washer head solves that in the head itself: the flange is formed with the hex, it cannot be dropped, and it spreads the clamp over an area wider than the flats.
The flange also changes the bearing surface under load. A plain hex head bears on its across-flats diameter; the flange extends past it and gives a flat annulus, which on a thin panel or a coated frame is the difference between a firm joint and a ring mark. Because the flange is stainless and uncoated, it also slides against the panel without a coating to wear off.
Length is where the torque goes. On long stainless screws the shank acts as a torsion spring, and part of what the wrench applies is taken up twisting the shank before the thread turns. That is why a long screw is driven steadily rather than hard, and why the thread has to be a good fit in its tapped hole — a tight thread on a long shank can stall the screw before it has seated the joint.
Stainless adds one more consideration to that. A2 against A2 galls when driven dry under pressure, and the longer the thread engagement the more contact there is to gall. A lubricant at assembly, or a pair of dissimilar grades, is the usual control, and on a long screw it matters more than on a short one because there is more thread to seize.
The half thread keeps the joint working as a clamp. The plain shank passes the clearance holes so the parts slide on a smooth surface, and only the last section threads into the far part. On a long stainless screw the plain section is most of the length, and its diameter is what the joint’s alignment depends on.
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 long stainless screws the quotation carries across flats, flange diameter, overall length, thread length, shank diameter and grade.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Hex washer head | Across flats, height and flange diameter |
| Flange | Integral flat annulus | Flatness and edge condition |
| Shank | Plain section through the joint | Diameter and length |
| Thread | Half thread at the tip | Thread length, pitch and gauging |
| Material | A2 stainless | Grade and heat number on the certificate |
| Finish | Passivated | Surface condition and flange face |
| Relief | Undercut under the flange | Depth and corner form |
Flange diameter is the number to specify against the panel. It is larger than the hex and it is what spreads the load, so a flange one size down no longer does the job the head was chosen for.
Thread length and plain length belong on the drawing separately. On a long screw the division between them is the joint: a thread that starts too early grips the stack, and one that starts too late does not engage enough turns in the far part.
Three features define the part: the flange, the long shank and the stainless body. The first replaces a washer, the second gives the reach, and the third removes the coating question from every surface that matters.
| Feature | What it gives | What it costs |
|---|---|---|
| Flange | Clamp spread without a washer | Larger head footprint |
| Long shank | Reach through a spacer or stack | Twists under driving torque |
| Hex head | Wrench drive, high torque | Head stands above the surface |
| Half thread | Thread only where it works | Both lengths must be specified |
| Passivated A2 | No coating on flange or thread | Softer than steel; galls dry |
The flange is the practical feature on a joint that is opened. A washer that lives on a long screw is a washer that gets lost, and a flanged head is the same protection with nothing to drop.
The stainless body is the other practical choice. On a long part exposed to moisture, a plated coating is thinnest and most rubbed exactly where the shank passes through the joint, and stainless removes that failure point entirely.
The recorded finish is passivation with no coating on A2 stainless. On a long screw that is the right answer for a reason beyond corrosion: nothing is added to the flange face or to the thread, so the bearing surface and the thread fit are exactly what the drawing specifies from the first piece to the last.
| Option | How it protects | Effect on flange and thread | Typical use |
|---|---|---|---|
| A2 stainless, passivated | Passive chromium oxide film | Flange and thread as made | Outdoor and wash-down joints |
| A4 stainless, passivated | Passive film with molybdenum | Flange and thread as made | Marine and chemical |
| Steel, zinc plated | Sacrificial zinc | Build on flange and thread; re-gauged | Indoor general work |
| Steel, Dacromet | Inorganic zinc-aluminium layer | Build allowed at the thread | Wet outdoor hardware |
| Titanium | Native oxide, light body | Flange and thread as made | Weight-critical joints |
The A2 and A4 choice follows the environment, and on a long screw it is worth making deliberately. A2 handles ordinary exposure; A4 is for chlorides, which on a long fastener usually means a marine fitting or a wash-down line where the shank is permanently wet.
Where steel is chosen for cost, the flange face is the surface to check after plating. It bears on the panel, so a rough deposit there marks the surface the flange was fitted to protect.
Three assemblies where long stainless screws are the fixing:
| Where it sits | The screw passes through a frame and a spacer into a tapped insert, and the joint is cleaned or rained on through its life. |
| When it goes wrong | A plated screw rusts at the shank where it rubs in the clearance holes. |
| Why it happens | The joint is long, it is wet, and it is serviced outdoors. |
| What we control | Grade confirmed on the certificate; first article assembled in the frame. |
| Where it sits | The screw holds a guard at a stand-off where a washer would be lost every time the guard is removed. |
| When it goes wrong | The flange is under-sized and the guard panel dishes at the fixing. |
| Why it happens | The joint sets a distance, the panel is thin, and the head is exposed. |
| What we control | Flange diameter and face flatness checked; first article fitted. |
| Where it sits | The screw joins two members of a frame at a distance, with the head on the outside where it is seen. |
| When it goes wrong | A long shank twists under the wrench, and the joint never seats. |
| Why it happens | The joint spans a gap, the drive is a wrench, and the load is structural. |
| What we control | Thread fit and shank diameter checked; driving tested on the first article. |
Four reasons that matter on a long flanged part, each tied to what the drawing has to prove:
|
Flange, lengths and grade agreed
Flange diameter, across flats, thread length, plain length and grade are agreed as a set, because on long stainless screws the head and the division both decide the joint. Basis: Flange, lengths and grade agreed. |
Headed, threaded, passivated in one route
The hex and flange are formed, the half thread rolled and the parts passivated within one route, so the flange face and thread stay concentric to the shank. Basis: One route from wire to passivated screw. |
|
Flange and shank checked
The flange is checked for diameter and flatness and the shank for diameter along its length, because both are bearing or sliding surfaces. Basis: Flange and shank checked. |
First article assembled in the joint
The first article is assembled into the customer frame or spacer, because the plain length only proves itself there. Basis: First article assembled in the joint. |
Shi Shi Tong forms long stainless screws on multi-station headers that form the hex and the flange in one strike, draws the long shank, rolls the half thread at the tip and passivates the parts. The first part of every run is measured on across flats, flange diameter and flatness, overall length, thread length and shank diameter before the batch continues.
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The flange is where the head is decided. The punch has to push stainless outward into a flat annulus without cracking it at the corner where the flange meets the hex, and stainless work-hardens as it is formed; a punch that is slightly worn leaves a flange that is thin at one side and will deform under the wrench.
What decides whether long stainless screws pass is the flange, the hex, the shank and the thread. The inspection agreement covers those, and the criteria come from the drawing.
Head and flange on the projector |
Thread gauged per batch |
Hardness checked on the wire |
Salt-spray testing of the grade |
The flange is measured for diameter and checked for flatness, the hex for across flats and height, and the shank for diameter along its length. The thread is gauged per batch, and the grade is confirmed on the mill certificate rather than by appearance.
The first article is assembled into the customer joint and the head checked for how it bears on the panel. A flange that measures correctly and marks the panel has still failed the purpose it was specified for.
Every shipment of long stainless 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 flange and the same lengths.
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 long stainless screws the first article is assembled in the customer joint, because the plain length is what the joint feels. 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 |
The flange is part of the head, so it cannot be lost when the joint is opened, and it spreads the clamp the same way a washer would.
The plain shank passes the clearance holes and the thread engages at the far end, so the parts are clamped rather than threaded.
The shank twists under load, so part of what the wrench applies is absorbed before the thread turns. Steady driving and a correct thread fit matter more than force.
A2 against A2 can gall when driven dry. A lubricant at assembly, or a pair of dissimilar grades, is the usual control.
Thread length from the tip and plain length from the head, both quoted separately.
Across flats and head height, flange diameter, overall length, thread length, shank diameter, the grade and the finish.
How a long stainless screw project runs from drawing to repeat delivery:
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1
Send the drawing and the joint it spans
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→ |
2
Flange, lengths and grade agreed
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→ |
3
First article assembled in your joint
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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 across flats and head height, flange diameter, overall length, thread length, shank diameter, the grade and the finish.
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Head A/F
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Flange diameter
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Overall length
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Thread length
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Shank diameter
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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
