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:Star Shaped Screw, Star Drive Screws
Materials:Carbon Steel
Surface treatment:White Zinc Plated
Head Type:Flat Head (CSK)
Drive:Six-lobe star recess (Torx)
Thread:Self-tapping
Point:Sharp, tapered
Forming:Single Die Heading
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10
Number:863
We make star drive screws in carbon steel with a white zinc plate, a countersunk head, a self-tapping thread and a sharp point, quoting them from M1 to M10. Cone angle, star size, thread and point come from your drawing, and the first article is driven into your own panel.
Watch the factory video·Email sst@szsst88.com
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.
Star drive screws are driven by a six-lobe recess and, in this form, carry a countersunk head and a sharp self-tapping point. The part recorded here is carbon steel with a white zinc plate, quoted from M1 to M10 with Number 863.
Star drive. Six rounded lobes engaged by a bit that pushes on the lobe walls, so torque is carried without lifting the bit.
Countersunk head. A cone that seats in the countersink so the head finishes flush.
Self-tapping thread. A hardened thread with a sharp point that forms its way into sheet, plastic or soft metal.
White zinc. A thin bright deposit over carbon steel, applied after threading, that protects the part in dry and indoor conditions.
These screws are used in appliances, furniture, electrical accessories and light sheet work, where a flush head, a reliable drive and a low unit cost all matter at once.
The drive is the point: six lobes spread the load and keep the bit seated.
A self-tapping screw has to form its own thread, and that takes more torque than driving into a tapped hole. On a small countersunk head there is very little room for a recess, so the drive has to transmit that torque from a shallow shape. A star recess does it better than a cross: the bit loads the lobe walls along their length instead of the arm tips, so it keeps its grip while the thread is being formed.
The countersunk head then takes something away. The cone has to sink into the material, which means the sheet is countersunk or formed before the head seats, and the thread then grips in what remains. On a thin panel the joint at the head is thinner than the sheet itself, and that is a property of the head form rather than of the supplier.
The sharp point is what makes the joint possible without a second operation. It starts in a drilled or punched hole and forms the thread as it enters, so the assembly needs a hole and a driver rather than a hole, a tap and a driver. The point also has to be concentric: a point that sits off-centre starts the screw at an angle, and a countersunk head then beds on one side of the countersink while the other stays proud.
White zinc is the part that decides where these screws can be used. The plate protects the head and the shank, and it is applied after threading so the thread crest is covered too — but the crest is exactly where the coating is scraped off as the thread forms. What is left in the material is bare steel, and in a damp joint that is where the rust starts, inside the joint where it cannot be seen.
So the honest position is that these are indoor fasteners. Where the joint is dry, closed or covered, the zinc is enough and the cost is right. Where the joint is wet or outside, the same head and drive in stainless is the correct part, and the price difference is small against the cost of a rust bleed.
The recorded range is M1 to M10, with lengths made to the drawing. Custom lengths up to 2,000 mm are subject to DFM review after drawing submission. For star drive screws the quotation carries head diameter, cone angle and thickness, the star size and recess depth, thread pitch, point form and overall length.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Countersunk, 90-degree cone | Diameter, angle, thickness and rim |
| Recess | Six-lobe star | Size, depth, lobe form and floor |
| Thread | Self-tapping | Pitch, core diameter and crest condition |
| Point | Sharp, tapered | Point length and concentricity |
| Length | Overall, head included | Length tolerance and thread start |
| Finish | White zinc | Coating thickness and recess re-gauged |
The star size belongs on the drawing as a number. At small diameters a bit one size up will enter far enough to feel engaged and then ream the lobes, and on a countersunk head there is no edge to grip afterwards.
Cone angle is quoted with the countersink it will sit in. A head of one angle in a countersink of another touches on a ring, rocks under load and leaves a gap at the rim, which on a flush joint is immediately visible.
Four features define star drive screws in this form, and each one is a trade:
| Feature | What it gives | What it costs |
|---|---|---|
| Star recess | Torque for a forming thread | Only the right bit fits; a worn one reams the lobes |
| Countersunk seat | Flush finish | Removes material where the thread holds |
| Sharp point | Forms its own thread | Pilot hole tolerance is narrow |
| White zinc | Bright, cheap, adequate indoors | Scraped off where the thread forms |
| Carbon steel | Strength at low cost | Rusts inside the joint if it gets damp |
The drive is what makes a cheap forming screw work on a line. A screw that has to cut its own thread needs sustained torque at a small head, and a star recess delivers it where a cross would climb out before the thread is formed.
The zinc is where the saving is made and where the risk sits. A coated carbon steel screw costs a fraction of a stainless one and does the same job indoors; the failure only appears when the joint is exposed, and it appears from the inside.
The recorded finish is white zinc over carbon steel. It is thin and bright, applied after threading, and it is the finish that keeps the cost of this screw low enough for high-volume indoor work.
| Option | How it protects | Effect on recess and thread | Typical use |
|---|---|---|---|
| White zinc | Sacrificial zinc, thin | Recess re-gauged; crest scraped at forming | Indoor assemblies |
| Colour zinc | Sacrificial zinc, thicker | More build; thread re-checked | Appliances and furniture |
| Black zinc | Sacrificial zinc, dark | Same build; wear shows earlier | Dark housings |
| Zinc nickel | Alloy coating, higher salt resistance | Build noticeable; both gauged | Outdoor and automotive |
| Stainless, passivated | Passive film, no coating | Point and recess as formed | Wet and food areas |
Where the joint is indoors, white zinc is the right cost. Where it is damp, a heavier coating buys time and nothing more, because the coating is still scraped at the thread. Where the joint is genuinely wet, the material has to change rather than the finish.
Where a coating is applied, the recess is gauged after plating. A star recess is narrow at the lobes, so a zinc layer is a larger fraction of the usable depth than it would be in a cross.
Three assemblies where a flush star-drive forming screw is the standard:
| Where it sits | The screw closes a panel or fixes a bracket where the head must sit flush and the line drives it with a power tool. |
| When it goes wrong | The bit climbs out and marks the paint around the head. |
| Why it happens | The panel is thin, the head is flush, and the drive is powered. |
| What we control | Recess gauged with the production bit; first article driven into a sample panel. |
| Where it sits | The screw joins a panel where the head disappears into a countersink and the joint is closed on site. |
| When it goes wrong | The seat angle does not match and the head stands proud. |
| Why it happens | The seat is machined or formed, the face is visible, and the head has to be flush. |
| What we control | Cone angle and recess checked; first article seated in the customer panel. |
| Where it sits | The screw forms its own thread in a thin section where a tapped hole or an insert would add an operation. |
| When it goes wrong | A pilot hole that is too small splits the material; one that is too large never holds. |
| Why it happens | The section is thin, the thread is formed by the screw, and the head is flush. |
| What we control | Pilot hole agreed; first article driven into a sample section. |
Four reasons that matter on a flush star-drive forming screw, each tied to something the drawing has to prove:
|
Star size and cone agreed
Star size, recess depth and cone angle are agreed as a set, because on a countersunk head all three share one thickness. Basis: Star size and cone agreed. |
Formed, rolled and plated in one route
The cone and star recess are formed in one stroke, the thread rolled, the point cut, and the parts plated in the same sequence. Basis: One route from wire to plated screw. |
|
Recess proved with the bit
The recess is proved with the production star bit, because a recess that measures correctly can still refuse a worn one. Basis: Recess proved with the bit. |
First article in your panel
The first article is driven into the customer panel at the line setting, because the countersink and the pilot hole belong to the pair. Basis: First article driven in the panel. |
These screws are headed on single-die machines that form the countersunk cone and cut the star recess in one stroke, rolled with the self-tapping thread, cut to a sharp point and plated as a batch. The first part of every run is measured on cone angle, recess depth, thread, point and length.
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Cutting six lobes into the flat top of a cone sets the life of the part. The punch reaches depth across a face only a few millimetres wide and has to leave material between the recess floor and the cone; on a countersunk head that gap is the thinnest section of the fastener, and a punch set a little deep gives a head that gauges correctly and splits at the rim.
The point is cut after the thread is rolled and checked for concentricity. A point that is off centre makes the screw walk in the pilot hole, and in a countersunk joint the result is a head that beds on one side and stands proud on the other — visible on any flush panel.
What decides whether star drive screws pass is the cone, the recess, the thread and the point. The inspection agreement covers those, and the criteria come from the drawing.
Cone and recess on the projector |
Thread and point checked |
Point and core hardness |
Salt-spray testing of the zinc layer |
Cone angle is measured against a master and proved on a countersink block, head thickness is measured in the same pass, and the recess is proved with the production bit. The point is checked for length and concentricity, because an off-centre point is what turns a flush seat into a tilted one.
A sample from every batch is driven into the customer’s panel and removed. That cycle shows a stripped thread, a proud head or a reamed recess, and none of them appear in a dimensional record.
Every batch is traceable to the wire it was made from and to the plating lot that finished it. The grade and heat number appear 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 shipment we supply the material certificate, the inspection record for the dimensions on the drawing and the plating thickness report. The documents carry the drawing revision and the batch number, so a repeat order keeps the same recess and the same point.
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 star drive screws the first article is driven at the line setting, because the recess and the forming torque are decided together. Buyers visit during the process to review samples.
|
8,678+
customers served
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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 star bit of the size on the drawing. A bit one size up enters partway and reams the lobes.
A forming thread needs sustained torque at a small head; the lobes hold the bit where a cross would climb out.
No. The coating is scraped off where the thread forms, and rust starts inside the joint.
Yes. The sharp point forms the thread in a drilled or punched hole; without one it will not start cleanly.
It can. The recess is re-gauged after plating, because the lobes are narrow and the depth is limited.
Head diameter, cone angle and thickness, star size, thread pitch, point and length.
How a star drive screw project runs from drawing to repeat delivery:
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1
Send the drawing and the panel
|
→ |
2
Star size, cone and point agreed
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→ |
3
First article driven at line setting
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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, cone angle and thickness, star size, thread pitch, point and overall length.
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Head size
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Cone angle
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Star size
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Thread pitch
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Point
|
Length
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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
