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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:Hexagon Slotted Screws
Materials:Carbon Steel
Surface treatment:Eco Friendly Black Zinc Plated
Head Type:Wide flat disc head
Drive:Hexagon socket with slot
Thread:Machine thread
Point:Plain, chamfered
Forming:Cold heading; socket and slot cut; thread rolled
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M12 M14 M15
We make hexagon slotted screws in carbon steel with a wide flat head that carries both a hexagon socket and a straight slot, black zinc plated and quoted to the head on the drawing. The slot cuts across the socket and removes two opposite flats, so the hexagon carries less torque than a plain socket of the same size.
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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.
A hexagon slotted screw has two drives on one head: a hexagon socket in the centre and a straight slot cut across it, so either an Allen key or a flat blade can turn it. This part is carbon steel with a wide flat head, a short thread and an eco black zinc finish, and is quoted with the head and length made to the drawing.
Combination drive. A hex socket with a slot through it, so two different tools will fit.
Wide flat head. A broad, low disc that spreads the load over thin or soft material.
Short thread. A body only a few turns long, for a shallow tapped hole or a thin panel.
Black zinc. A thin, uniform dark finish that leaves the slot and the socket as machined.
They are used in instruments, cameras, display panels and small covers, where the same fixing may be serviced by an assembler with a driver and by a user with a small Allen key.
A combination drive looks like a convenience and behaves like a compromise. The socket is sized to take a hex key; the slot is cut straight across it, and in doing so it removes most of two opposite flats. What is left is four flats of full width and two short stubs, so the effective bearing area of the socket is smaller than its size suggests.
On hexagon slotted screws that matters because the torque still goes through those flats. A key that fits the socket will seat, feel correct, and then load only the four remaining flats; the two interrupted ones contribute nothing at the point where the key is trying to turn. So a hexagon slotted screw of a given socket size carries less torque than the plain hex socket it is copied from, and the difference shows up as rounded flats rather than as a clean failure.
On hexagon slotted screws the slot has its own limit. It is a straight cut with square ends, and those ends are stress raisers in the thinnest part of the head. On a wide flat disc the material under the slot is thinner than under the rest of the head, so a screw driven hard with a blade can crack through the slot end into the socket.
On hexagon slotted screws the head height ties both of them together. A wide disc head is thin by design, and the socket plus the slot consume most of that thickness, leaving a shallow socket and a shallow slot. A shallow socket means the key engages over less length; a shallow slot means the blade has less to sit in and climbs out earlier.
On hexagon slotted screws the finish does not change any of this, which is one reason a thin black zinc suits the part: the film adds nothing to the socket and the slot, so the key and the blade fit the dimensions that were machined and measured.
The practical consequence for hexagon slotted screws is a part that is easy to drive and modest in torque. It belongs on joints that are tightened once and checked, not on a joint that will be pulled up hard, and the drawing should say so rather than leave the torque to the bench.
Hexagon slotted screws are quoted by thread size and pitch, length, head diameter and height, socket across-flats and depth, slot width and depth, and finish. Custom lengths up to 2,000 mm, subject to DFM review after drawing submission. The quotation carries the material, the head, both drives, the thread and the plating.
| Item | How it is defined | What we control |
|---|---|---|
| Body | Carbon steel | Grade and hardness |
| Head | Wide flat disc | Diameter, height and bearing face |
| Socket | Hexagon socket | Across-flats and depth |
| Slot | Straight slot across the socket | Width, depth and end radius |
| Thread | Machine thread | Size, pitch and length |
| Finish | Eco black zinc | Thickness and colour |
The socket and the slot are written as a pair, because cutting one changes what is left of the other. A slot that is wider than the drawing removes more of the hexagon; a socket that is deeper leaves less material under the slot.
The slot end radius is specified rather than left square. It is where a crack starts on a hard-driven part, and a radius costs nothing on the drawing and a lot on the line if it is missing.
The head height is checked before the length, because on a wide disc head it is the dimension that limits both drives. A customer who wants the head flatter is usually asking for a shallower socket and a shallower slot at the same time.
Four properties decide this part, and each carries a cost:
| Property | What it gives | What it costs |
|---|---|---|
| Combination drive | A blade or a key will both work | The two drives reduce each other |
| Wide flat head | Bearing area on thin material | A thin disc with little depth for tools |
| Short thread | A low profile in a shallow hole | Few turns of engagement |
| Black zinc | Uniform dark finish, thin film | Wears at the slot and the socket |
The value is one fixing that two different people can open with two different tools, in a flat head that sits low and covers a wide area on a thin panel, on a joint that is set once and checked rather than pulled up hard.
The cost of hexagon slotted screws is that neither drive is as strong as it would be alone, and the head has no spare thickness to give either of them more.
The recorded finish is eco black zinc. On this head the finish is judged by whether the slot and the socket still take their tools: the film is thin, so both drives keep the dimensions they were cut to, and the colour is uniform across the dome and down into the recess.
| Option | How it protects | Effect on the drives | Typical use |
|---|---|---|---|
| Eco black zinc | Sacrificial zinc plus dye | Thin; slot and socket unchanged | Instruments and panels |
| Black oxide | Conversion layer | Nearest to zero build | Dry indoor parts |
| Nickel | Hard barrier layer | Builds; both drives re-checked | Visible hardware |
| Zinc-nickel | Thicker alloy layer | Build; slot width re-gauged | Damp service |
| Plain | None | No build; rusts in damp | Trial samples |
Where the coating is heavier, the slot is the first feature to suffer: it narrows, the blade no longer bottoms, and the drive becomes a cam-out. That is why a combination head is usually finished thin.
Black zinc also hides the wear that matters. A slot that has been driven hard shows bright edges before it cracks, and on a black head that is easy to see in inspection.
Three products where a flat head and two drives earn their place:
| Where it sits | The screw closes a cover where the face has to stay flat and the fixing is serviced by two different trades. |
| When it goes wrong | The socket rounds, or the slot spreads under a blade. |
| Why it happens | Both drives are shallow in a thin head, and the torque is set by feel. |
| What we control | Head height, socket depth and slot width checked; both drives tested on the sample. |
| Where it sits | The screw sets a small plate that is adjusted with a key and locked with a blade. |
| When it goes wrong | The plate shifts after adjustment, or the head marks the mounting face. |
| Why it happens | The disc head is not flat on its bearing face, and there is no locking element. |
| What we control | Bearing face flatness and thread agreed; sample adjusted and locked. |
| Where it sits | The screw holds a face panel that is assembled in quantity and opened rarely. |
| When it goes wrong | The heads stand out of the panel, or the finish flakes at the slot. |
| Why it happens | The head is thicker than the counterbore, and the coating builds in the slot. |
| What we control | Head height and coating thickness specified; sample fitted into the panel. |
Four points that decide whether a combination head still takes its tools after plating and handling:
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Socket and slot on one sheet
The drawing carries both drives with their depths, because cutting one changes what is left of the other. Basis: Drives specified together. |
Cut, then plated
The socket and the slot are cut to size and checked with the key and the blade after plating, not before. Basis: Tools fit the finished part. |
|
Driven both ways
The first article is driven with a blade and with a key, and the socket is inspected for rounded flats. Basis: Both drives proved. |
Same head every lot
Head height, socket depth and slot width are recorded with the drawing revision, so a repeat batch takes the same tools. Basis: Same drives across lots. |
A combination head is bought for convenience and judged by whether it still turns. These four points are what keeps both drives usable instead of one of them becoming decoration.
These screws are cold headed from carbon steel wire, with the wide flat head formed in the die and the hexagon socket and the slot cut in following operations, and the thread rolled before plating. The first piece of every run is measured on head diameter and height, socket depth, slot width and depth, thread and length.
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The socket is cut first and the slot second, because the slot crosses the socket and has to be centred on it. A slot that is a little off centre leaves one flat much narrower than the others, and that narrow flat is the one that rounds first.
The head is wide and thin, so the cutting operations have less material to work in than on a taller head. Depth is the dimension to watch: a few hundredths too deep in either the socket or the slot starts to break through into the bearing face, and the head then fails at the seat.
Plating follows the machining and is kept thin. The slot is a narrow opening, and a film that is heavier than the drawing closes it enough to change the blade fit; that is checked on the plated parts rather than on the blanks.
What decides whether a batch of hexagon slotted screws passes is the socket that takes the key, the slot that takes the blade and the head that seats. The inspection agreement covers all three.
Head, socket and slot on the projector |
Thread checked with gauges |
Material checked |
Salt-spray testing of the coating |
The socket is measured for across-flats and depth and checked with the key; the slot is measured for width and depth and checked with the blade. Both drives are tested on the same part, since the question is whether either of them has been sacrificed to the other.
The head is measured for diameter and height and checked for a flat bearing face. On a disc this wide a slight dish turns the bearing face into a ring at the rim, and the head marks the panel it was meant to protect.
The slot ends are inspected for radius and for cracks after the drive test. A square-ended slot in a thin head is the first place a hard-driven part fails, and it shows as a hairline at the end of the slot.
Every batch of hexagon slotted screws is traceable to the wire, the heading lot and the plating lot. The material certificate states the grade, the heat number and the mechanical properties; the plating record carries the coating thickness and the lot, and the inspection record carries the head, both drives and the thread.
ISO 9001:2015 |
RoHS test report |
Registered trademark |
Patent: security screw and driver |
With each shipment we supply the material certificate, the inspection record for the head, socket, slot and thread, and the plating record. The records carry the batch number, so a repeat order can be compared with the first on the two drives that decide whether the part can still be opened.
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 combination head the first article is driven both ways, because a part that takes one tool and not the other has lost half its purpose. Buyers visit during the process to review samples.
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8,678+
customers served
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87%
of orders from repeat customers
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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 heading and cutting stations 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 |
So a blade or a key will both turn the screw. It suits assemblies that two different trades may open.
The hexagon. The slot removes two flats, so the socket carries less torque than a plain one of the same size.
Because the slot left only four full flats, and a worn key loads them harder. It is a design limit, not a defect.
Only with a deeper socket and a thicker head, or by using a plain socket version instead.
A thin zinc does not. A heavy coating narrows the slot and closes the socket, so both are checked after plating.
Head diameter and height, socket size and depth, slot width, depth and end radius, thread and length.
How a hexagon slotted screw project runs from drawing to repeat delivery:
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1
Send the drawing and the panel sample
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→ |
2
Head, socket and slot agreed
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→ |
3
First article driven both ways
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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 used for 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, slot width and depth, thread and length, and the finish.
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Head
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Socket
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Slot
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Thread
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Length
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Finish
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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
