Tel：
+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:Round Head Bolt
Materials:Carbon Steel
Surface treatment:Blue Zinc Plated
Head Type:Button Head
Drive:Hexagon socket (Allen)
Thread:Machine thread
Point:Blunt
Forming:Headed
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10
We make button head socket bolts in blue zinc plated carbon steel, with a low domed head, a hexagon socket and a machine thread, quoting them from M1 to M10. Head height, socket depth, thread and finish 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.
Button head socket bolts are fasteners with a low domed head, an internal hexagon and a machine thread, used where a fixing has to sit low and be driven from above. This one is carbon steel with a blue zinc finish, quoted from M1 to M10 with the flat head form to ISO.
Button head. A shallow dome on a small bearing face, smooth to the touch and low enough to sit inside a recess.
Socket drive. An internal hexagon cut into the dome, driven with an Allen key.
Machine thread. A rolled thread for a tapped hole or a nut, ending in a blunt chamfer.
Blue zinc. A bright zinc deposit with a blue-white chromate, the economical indoor finish for steel fasteners.
Button head socket bolts are used where the head has to be smooth and low but the drive still has to be positive: guards, covers and housings that are handled, and assemblies where a moving part passes close to the surface.
A button head socket bolt is bought for its profile, and the profile is also its limit. The dome leaves less material above the hexagon than a cylindrical cap head does, so the socket is shallower and the key engages less of its length. The bolt is therefore a low-head fixing with a low-head torque, and the joint has to be designed around that rather than around what the thread could carry.
That difference shows up in service rather than on the drawing. A cap head of the same thread can be tightened hard without the key slipping; a button head at the same torque starts to feel soft, and a worn key rounds the corners of the socket. The usual result is a fixing that cannot be removed without drilling, which is a poor outcome for a part chosen because it looked neat.
What the head gives is worth the care. The dome has no edge to catch a cloth, a hand or a cable, and it sits low enough that a cover can pass over it. On equipment that is handled, or where a moving part runs close to the surface, the button head is often the only form that works without a counterbore.
Blue zinc is the finish that matches the economics. It is a thin, bright, sacrificial deposit, gauged after plating so the thread still runs, and it protects steel indoors where the part is not washed or abraded. On a button head it also keeps the socket usable, because no thick coating is added to a recess that is already shallow.
The bearing face under the dome is small, which matters on soft material. A button head concentrates the clamp on a narrow ring; on a plastic panel or a thin sheet a flanged button head or a washer is the correction, and the plain button head is the wrong part for that joint.
The recorded range is M1 to M10, with custom lengths up to 2,000 mm subject to DFM review after drawing submission. For a button head socket bolt the quotation carries head diameter and height, socket size and depth, thread and finish, because the head height is what bounds the socket and the socket bounds the torque.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Button head, domed | Head diameter and height |
| Socket | Internal hexagon, shallow | Across flats, depth and corner condition |
| Thread | Machine thread | Pitch, length and gauging after plating |
| End | Blunt, chamfered | Chamfer cut, not deburred |
| Material | Carbon steel | Grade and heat number on the certificate |
| Finish | Blue zinc plated | Thickness and colour |
| Standard | ISO | Head and socket dimensioning |
Socket depth deserves its own line on the drawing. Two suppliers can both make a button head to the ISO form and cut the hexagon to different depths, and the torque one bolt will take is not the torque the other will.
Head height follows the same logic. A lower dome looks better and drives worse; where the joint is tightened to a figure, the taller of the available head heights is the safer specification.
Three features define the part: the domed head, the shallow socket and the plated steel body. The first keeps the fixing out of the way, the second is the drive, and the third is what makes the part affordable in the quantities these are used.
| Feature | What it gives | What it costs |
|---|---|---|
| Domed head | Nothing to catch or cut | Shallow socket, lower torque |
| Small bearing face | Low footprint | Dimples a soft panel sooner |
| Socket drive | Common key, good grip | Rounds if over-tightened with a worn key |
| Blue zinc | Bright, thin, sacrificial | Not for wet or abrasive service |
| Carbon steel body | Strength at low cost | Depends on the coating for corrosion |
The economics are the practical argument. A steel button head with blue zinc costs a fraction of a stainless one, and for an indoor joint that is assembled once and not washed, the coating does the job the stainless body would have done.
The limit is the socket. Every part in this family shares a shallow hexagon, and the failure that matters is a rounded socket on a bolt that is otherwise perfect.
The recorded finish is blue zinc plating over carbon steel. It is a bright, thin, sacrificial deposit with a blue-white chromate; it looks like a finished fastener, it costs little, and it protects the steel until the coating is rubbed through. On a button head the thinness is an advantage, because the socket is shallow and any coating narrows it.
| Option | How it protects | Effect on socket and dome | Typical use |
|---|---|---|---|
| Blue zinc plated | Sacrificial zinc, bright | Thin build; socket as cut | Indoor general machinery |
| White zinc plated | Sacrificial zinc, bright | Thin build; same | Indoor assemblies |
| Black zinc plated | Sacrificial zinc, dark | Thin build; wear visible | Dark housings |
| Nickel plated | Hard barrier deposit | Socket narrowed; re-checked | Visible consumer parts |
| Stainless alternative | Passive film, no build | Socket and dome as made | Wet and food service |
Where the joint is wet, blue zinc is the wrong choice and the answer is stainless rather than a thicker coating. A coating thick enough to survive a washdown is thick enough to blunt the socket, and the part loses the drive it was chosen for.
Where the joint is dry and the bolts are visible, nickel is the upgrade: it is harder, brighter and does not wear through at the dome, at the cost of narrowing the socket slightly and needing a re-check after plating.
Three assemblies where button head socket bolts are the fixing:
| Where it sits | The bolt closes a guard where a hand or a cable passes over the surface and an edged head would catch. |
| When it goes wrong | The socket rounds on a bolt tightened with a worn key, and the guard cannot be removed. |
| Why it happens | The head is exposed, it is low, and the joint is serviced. |
| What we control | Socket depth checked; first article driven with the production key. |
| Where it sits | The bolt holds a panel where the head must sit low and the finish has to look like part of the machine. |
| When it goes wrong | The zinc wears at the dome and the head looks old before the machine does. |
| Why it happens | The joint is visible, it is indoor, and the cost matters. |
| What we control | Coating checked; first article fitted on the panel. |
| Where it sits | The bolt fixes a part where a higher head would foul a moving component. |
| When it goes wrong | A proud head strikes the moving part, and the assembly fails. |
| Why it happens | The clearance is tight, the head is low, and the drive is from above. |
| What we control | Head height and socket checked; first article fitted in the assembly. |
Four reasons that matter on a low-head socket part, each tied to what the drawing has to prove:
|
Head height and socket agreed
Head height and socket depth are confirmed together, because the dome leaves a shallow hexagon and the torque has to fit inside it. Basis: Head height and socket agreed. |
Headed, threaded, plated in one route
The dome and hexagon are formed in one stroke, the thread is rolled and the parts are plated within the same route. Basis: One route from wire to plated bolt. |
|
Socket driven, not just measured
The first article is driven with the production key at the joint torque, because a socket that measures correctly can still round with a worn key. Basis: First article driven at joint torque. |
First article fixes the setting
The first article fixes the wire, the socket punch and the plating; repeat orders are compared against that record. Basis: First article signed off before the batch. |
Shi Shi Tong forms these button head socket bolts from carbon steel wire on headers that form the dome and cut the hexagon in one stroke, rolls the machine thread to a blunt chamfered end and blue zinc plates the finished parts. The first part of every run is measured on head and socket, driven with the production key and entered into a thread gauge before the batch continues.
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Cutting a hexagon into a dome is where the part is decided. The punch has to hold a curved top while it cuts six flats to full depth, and it wears at the corners; a worn punch leaves a hexagon that looks right from above and sits shallow at the base, so the key bears on the top of the flats and rounds them at a torque the joint has taken before.
What decides whether button head socket bolts pass is the socket, the dome, the thread and the plating. The inspection agreement covers those, and the criteria come from the drawing.
Dome and socket on the projector |
Thread gauged per batch |
Hardness checked on the wire |
Coating proved by salt spray |
The socket is checked across flats and for depth and driven with the production key; the head is checked for diameter, height and dome form. The thread is gauged after plating, and the coating is checked for thickness and colour against the approved sample.
The first article is tightened to the joint torque and then released. A socket that survives being driven and will not survive being loosened is still a part that fails, and the release is where a shallow hexagon shows.
Every shipment of these button head socket bolts is traceable to the wire it was made from and to the plating 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 coating. The documents carry the drawing revision and the batch number, so a repeat order is made to the same socket geometry that was approved.
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 a button head socket bolt the first article is driven at the joint torque, because the socket and the seat are the function. Buyers visit during the process to review samples and to see how the heads are formed.
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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 plating 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 dome leaves less material above the socket, so the hexagon is shallower. The drive, not the thread, usually limits the joint.
The bearing ring is small. On plastic or thin sheet a flanged button head spreads the load without adding height.
Yes, with a worn key or too much torque. Set the torque to the head and use the correct key size.
No. It is a thin indoor finish; for wet service a stainless body is the right specification.
The recorded range is M1 to M10, with other lengths made to drawing.
Head diameter and height, socket size and depth, thread size and length, the grade and the finish.
How a button head socket bolt project runs from drawing to repeat delivery:
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1
Send the drawing and the clearance it fits
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→ |
2
Head height, socket and torque agreed
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→ |
3
First article driven at your 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 size and length, the grade, the finish and the joint torque.
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Head diameter
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Head height
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Socket size
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Socket depth
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Thread
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Joint torque
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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
