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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:Slotted Fillister Head Machine Screws
Materials:Steel
Surface treatment:Black Zinc Plated
Head Type:Fillister Head
Drive:Single slot
Thread:Machine thread, half thread
Point:Blunt
Forming:Multi-station heading
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M14
Number:422
We make slotted fillister head machine screws in black zinc plated carbon steel, with a tall domed head, a deep slot and a half thread, quoting them from M1 to M14. Head height and slot depth, thread length and finish come from your drawing, and the first article is driven with your blade.
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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 slotted fillister head machine screws have a tall cylindrical head with a slightly domed top, a single deep slot and a half thread, in black zinc plated carbon steel, quoted from M1 to M14 with Number 422.
Fillister head. A tall cylinder with a shallowly domed top, higher than a pan head and narrower than a cheese head.
Single slot. A straight cut across the top, driven with a flat blade; the head height allows it to be deep.
Half thread. The plain shank runs through the joint and the thread engages only at the far end.
Black zinc. A dark sacrificial zinc deposit over carbon steel, for assemblies that should not stand out.
Slotted fillister head machine screws are the version of a slotted screw that can actually be tightened: the tall head leaves room for a deep slot, so the blade engages further and slips later than it would in a low head.
On slotted fillister head machine screws the head is tall for one reason: it gives the slot depth. On a pan head the slot is shallow because there is not much metal between the slot and the bearing face; on a fillister head there is, so the slot can be cut deeper, the blade engages further, and the drive takes more before it slips.
That makes slotted fillister head machine screws a slot-drive part that can actually be tightened. The slot still has only two driving faces, but a deep one with a blade that fits bears over a longer edge, and the load per unit area drops. On small machine screws where the alternative is a shallow slot in a low head, the difference at the screwdriver is obvious.
On slotted fillister head machine screws the tall head has a cost in clearance. It stands further above the surface than a pan head of the same diameter, which rules it out of any pocket that has to stay flat; fillister heads are used where the head is either visible and meant to be seen, or sitting in a counterbore that was cut for them.
The half thread belongs to the joint rather than to the head. The plain shank passes the clearance hole and the thread engages at the far end, so the front part is not threaded on the way in — the same division as any half-threaded machine screw.
Black zinc is the finish over all of it. It is thin and sacrificial, it keeps the slot sharp, and it gives the dark appearance that a fillister head is often wanted for: these heads are visible, and on dark equipment a bright plated head is the one thing that draws the eye.
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 slotted fillister head machine screws the quotation carries head diameter and height, slot width and depth, thread length and finish.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Fillister, tall, shallow dome | Head diameter and head height |
| Slot | Single deep cut | Slot width, depth and end radius |
| Shank | Plain section through the joint | Diameter and length |
| Thread | Half thread | Thread length, pitch and gauging |
| Material | Carbon steel | Grade and heat number on the certificate |
| Finish | Black zinc plated | Thickness and coverage in the slot |
| Process | Multi-station heading | Head form and slot depth |
On slotted fillister head machine screws the slot depth is the number that makes the head worth using, and it is limited by the head height. Quoting the two together tells a supplier what to aim for; quoting the slot alone leaves the head to whoever makes it.
Head height also has to be checked against the counterbore or the clearance above it. A fillister head in a pocket cut for a pan head will stand proud, and on a moving assembly that is a fouling point.
Three features define the part: the tall head, the deep slot and the half thread. The first gives the slot its depth, the second is the drive, and the third keeps the front part of the joint unthreaded.
| Feature | What it gives | What it costs |
|---|---|---|
| Tall head | Room for a deep slot | Stands above the surface |
| Deep slot | More blade engagement than a pan head | Two drive faces only |
| Half thread | Front part stays unthreaded | Both lengths must be specified |
| Black zinc | Dark finish for dark equipment | Thin; wear shows as a bright line |
| Domed top | A finished look | Slot shallower at the ends |
The deep slot is the reason to choose slotted fillister head machine screws over pan heads when the drive has to be a slot. It is still a slot, and it still should not be asked to take the torque of a socket head, but it is the version of a slot that works.
The height is the reason it is not used everywhere. Anything that has to pass over the fixing, or that sits in a shallow pocket, needs a lower head; the fillister is for open faces and deep counterbores.
The recorded finish is black zinc plating over carbon steel. It is a thin sacrificial deposit with a dark chromate, and on a tall head it has more area to cover than on a pan head — which is also why a patchy coating is more visible on it.
| Option | How it protects | Effect on slot and head | Typical use |
|---|---|---|---|
| Black zinc plated | Sacrificial zinc, dark | Thin build; slot and head as cut | Dark equipment and frames |
| Black oxide | Conversion film, oiled | No measurable build | Internal mechanisms |
| White zinc plated | Sacrificial zinc, bright | Thin build; brighter appearance | General indoor work |
| Nickel plated | Barrier deposit, bright | Slot narrowed; re-checked | Visible consumer parts |
| Stainless alternative | Passive film, no build | Slot as made | Wet and food service |
Where the joint is opened often, the dark finish wears at the slot first, because that is where the blade bears; the steel shows as a bright line along the slot. Black oxide wears more gradually than black zinc, because it is a conversion layer rather than a deposit.
Where the joint is wet, the material should change rather than the coating. A tall head with a deep slot collects water in the slot, and a rusted slot is a screw that cannot be turned.
Three assemblies where slotted fillister head machine screws are the fixing:
| Where it sits | The screw holds a cover where the head sits in a counterbore and the slot is driven with a flat blade at the bench. |
| When it goes wrong | The slot rounds because it was cut shallow, and the screw cannot be removed. |
| Why it happens | The head is tall, the drive is a slot, and the joint is serviced. |
| What we control | Slot depth and head height checked; first article driven and released. |
| Where it sits | The screw fixes a plate on equipment where the head is visible and a dark finish keeps it from standing out. |
| When it goes wrong | The black zinc wears at the slot and shows a bright line after a service. |
| Why it happens | The joint is visible, it is dark, and it is opened occasionally. |
| What we control | Coating checked; first article assembled twice. |
| Where it sits | The screw is part of the correct appearance of an instrument where a tall slotted head is the expected detail. |
| When it goes wrong | A lower head looks wrong, and a shallow slot will not take the blade. |
| Why it happens | The joint is period-correct, the head is seen, and the drive is a slot. |
| What we control | Head height and slot checked; first article fitted on the instrument. |
Four reasons that matter on a slotted tail head, each tied to what the drawing has to prove:
|
Head height and slot depth agreed
Head height and slot depth are agreed together, because on a fillister head the height is what allows the slot to be deep. Basis: Head height and slot depth agreed. |
Headed, slotted, plated in one route
The tall head is formed, the slot cut and the half thread rolled before the parts are black zinc plated within one route. Basis: One route from wire to plated screw. |
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Slot checked with the blade
The first article is turned with the customer blade and checked that it reaches the bottom of the slot without rocking. Basis: Slot checked with the blade. |
Slot depth recorded
The slot depth is recorded from the first article, so a repeat order drives the same way. Basis: Slot depth recorded. |
Shi Shi Tong forms the tall head of these screws on multi-station headers, cuts the single slot, rolls the half thread and black zinc plates the parts. The first part of every run is measured on head diameter, head height, slot width and depth, and thread before the batch continues.
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Cutting a deep slot into a tall head is easier than into a pan head, which is the point of the form, but the cutter still decides the part. Too deep and the head is weakened above the bearing face; too shallow and the blade rides on the top edges, which is the failure the tall head was chosen to avoid.
What decides whether slotted fillister head machine screws pass is the slot, the head, the thread and the finish. The inspection agreement covers those, and the criteria come from the drawing.
Head and slot on the projector |
Thread gauged per batch |
Hardness checked on the wire |
Coating proved by salt spray |
The slot is checked for width at the top and at the base, for depth and for the radius at each end, the head for diameter and height, and the thread for length and pitch. The coating is checked inside the slot.
The first article is driven and released with the customer blade. A slotted head that drives well and then will not release is a screw that has to be drilled out, and the tall head offers nothing to grip.
Every shipment of slotted fillister head machine screws 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 keeps the same head height and slot depth.
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 slotted fillister head screw the first article is driven with the customer blade, because the slot is the drive. 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 slotting and plating lines 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 |
To give the slot depth. A taller head has more metal above the bearing face, so the slot can be cut deeper and the blade engages further.
Yes, and that is the reason to choose fillister when the drive has to be a slot.
It sits in a counterbore, not a countersink. The head has a flat bearing face and does not go flush.
Somewhat, because the blade bears over a longer edge, but it is still a slot and not a high-torque drive.
The head is often visible, and a dark finish keeps it from standing out on dark equipment.
Head diameter and height, slot width and depth, thread length, the grade and the finish.
How a slotted fillister head screw project runs from drawing to repeat delivery:
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1
Send the drawing and the blade you use
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→ |
2
Head height, slot depth and thread agreed
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→ |
3
First article driven and released with your blade
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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, slot width and depth, thread length, the grade and the finish.
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Head diameter
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Head height
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Slot width
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Slot depth
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Thread 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
