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Email：sst@szsst88.com
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Address：Building 9, First Industrial Zone, Tantou Industrial City, Songgang Street, Baoan District, Shenzhen 518105, Guangdong, China
Type:CSK Pozi self tapping screw (countersunk, nickel plated)
Materials:Carbon steel
Surface treatment:Nickel plated
Head Type:Flat head, 90 degrees
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M14
Drive:Pozidriv (PZ)
Thread:Self tapping thread, blunt point
Forming:Cold heading; thread rolled, then nickel plated
Number:275
We manufacture CSK Pozi screws in carbon steel with a nickel finish, a 90 degree countersunk head and a blunt self-tapping point, quoted from M1 to M14 to a DIN form. Head angle, Pozi recess size, thread and plating thickness are taken from your drawing.
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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 CSK Pozi screw is a countersunk (CSK) self-tapping screw driven by a Pozidriv recess. The recorded item on this page is a carbon steel screw with a flat head, a nickel plated finish and a blunt self-tapping point, quoted from M1 to M14 to a DIN form.
Countersunk head. The 90° cone drops into a matching seat, so the head finishes level with the surface. On furniture, panels and appliance faces that is usually a requirement rather than a preference.
Pozidriv recess. A cross recess with four additional ribs set at 45° between the arms. The bit engages those ribs as well as the cross, so it holds more torque before camming out than a Phillips recess of the same size, and it needs a Pozi bit rather than a Phillips one.
Self-tapping thread, blunt point. The thread forms its own mating thread and the point is blunt rather than gimlet, which suits a pilot hole in sheet metal, a moulded boss or a board that has been pre-drilled.
Nickel plating. A bright, hard deposit that protects the steel and gives a silver tone that stays close to stainless in appearance. It is applied after the thread is rolled, so the thread is gauged in its plated condition.
Together these decide the part: the cone seats flush, the Pozi recess takes the torque, the self-tapping thread forms its own grip, and the nickel keeps the steel bright. That is why a pozi countersunk screw is specified by head angle, recess size, thread and finish together.
The body of this pozi countersunk screw is carbon steel wire, with the grade and heat number kept with the batch record. The property class is fixed on the drawing, because it sets the torque the head can take and whether the plated part needs a bake after coating.
The flat head and the Pozi recess are formed in one heading operation. The four ribs of the recess are part of the same die as the cross, so they are as deep and as sharp as each other; a recess formed in two steps can end up with ribs that do not all engage the bit, which defeats the point of the drive.
On a CSK Pozi screw the thread is rolled over the full length, with a blunt point. Rolling keeps the grain continuous and gives a smooth flank that forms its mating thread in a pilot hole without tearing the material, and the blunt point stops the screw from walking before the first thread bites.
The nickel is plated after the thread is rolled and the parts are cleaned. It builds a few microns on every surface, so the thread and the recess are gauged after plating rather than before, and the recess is driven with the matching Pozi bit in its finished condition.
The head of a CSK Pozi screw has a small flat on top of the cone, and that is where the recess sits. On a countersunk screw that flat is the thinnest part, so the recess depth and the cone depth come out of the same die setting and are checked on the same first article.
CSK Pozi screws of this type are quoted from M1 to M14; the recorded configuration covers that range in carbon steel with a nickel finish and a blunt self-tapping point. Custom lengths up to 2,000 mm are subject to DFM review after drawing submission, because the thread form and the recess are set before the roll and the die are made.
| Item | How it is defined | What we control |
|---|---|---|
| Head diameter and angle | The 90° cone that seats flush | Checked on the projector on the first article |
| Pozi recess size | Which PZ bit the head takes | Checked with the matching bit |
| Recess depth | Material left under the cone | Checked on the first article |
| Thread form and pitch | The grip in the pilot hole | Gauged after plating, per batch |
| Point form | Blunt, on centre | Checked on the first article |
| Length | From the top of the head to the point | Measured on the shop plate |
Each size is quoted against the seat and the pilot hole. The countersink angle, the head diameter and the pilot diameter are reviewed together, because a pozi countersunk screw that is right for one seat stands proud in another cut at a different depth.
Length on a CSK Pozi screw is measured from the top of the head to the point, and the recess is checked with the Pozi bit that will be used. A Phillips bit will start in a Pozi recess and will feel as if it fits, which is exactly why the check is done with the right bit rather than any cross.
The Pozi recess is the feature that defines the part, and the question worth answering is why it exists at all when a Phillips cross looks similar. The answer is cam-out: a Phillips bit rides up out of the recess as the torque rises, by design, while a Pozi bit engages four additional ribs and stays in the head at the torque that would have lifted a Phillips bit clear.
| Feature | Phillips | Pozidriv | What it means on the joint |
|---|---|---|---|
| Recess shape | Cross with tapered arms | Cross plus four ribs at 45° | Pozi takes more torque before it lifts |
| Bit required | PH0, PH1, PH2 | PZ0, PZ1, PZ2 | A PH bit will start but not drive to torque |
| Cam-out behaviour | Designed to lift as torque rises | Holds much longer | Fewer deformed recesses on a power driver |
| Head damage | Corners deform when over-driven | Ribs spread the load | The head survives repeated assembly |
The two drives are not interchangeable, and the mistake is common. A Phillips bit in a Pozi recess engages the cross and none of the ribs, so the screw feels tight, drives part way, and then cams out exactly as a Phillips would. The first article is therefore checked with a PZ bit, and the drawing names the bit size.
The blunt point of a CSK Pozi screw suits a pilot hole that has been prepared. On sheet metal that means a hole drilled or punched to the size on the drawing; in a moulded boss it means the boss has a cored hole. The thread forms its grip in that hole, and the blunt point stops the screw from wandering across the surface before the thread engages.
On a CSK Pozi screw the nickel plating and the recess interact: the film is thin, but it is thickest in the corners of the cross, which is where a bit first loses contact. The recess is therefore driven with the PZ bit after plating, not before, and the depth is set with that in mind.
This pozi countersunk screw is supplied nickel plated. The deposit is hard, bright and thin, and it gives a silver tone close to stainless, which is why it is used on visible furniture and appliance hardware where the screw should not read as a different metal from the panel.
| Finish | How it protects | Effect on recess and thread | Typical use |
|---|---|---|---|
| Nickel plated | Hard barrier layer, bright | A few microns; thread and recess gauged after | Visible furniture and appliance hardware |
| Zinc plated | Sacrificial zinc layer | A few microns; gauged after | Indoor assemblies, low cost |
| Zinc nickel | Alloy layer, higher corrosion resistance | Thicker; thread re-checked | Wet or mildly corrosive service |
| Black oxide | Conversion layer plus oil | No build-up | Indoor dark parts |
| Stainless (equivalent part) | Alloy provides protection | No coating; as formed | Wash-down and outdoor work |
Nickel on steel needs care at the sharp edges, and on a CSK Pozi screw the recess carries most of that risk. A plated recess has plating on the rib edges, and those edges are where the bit loads; if the deposit is brittle it flakes at the first hard drive and leaves a bright spot in a dark recess. The first article is driven at the joint torque to check exactly that.
Where the joint will be exposed to water, a CSK Pozi screw in nickel plated carbon steel is not the right choice and the drawing should call for a stainless part or a coating with better corrosion performance. Nickel protects the surface it covers; it does not protect a scratch the way zinc does.
Packing keeps the cones and the recesses of a CSK Pozi screw apart. The parts are bagged in counted quantities, labelled with the batch, the material heat and the bit size, and packed so the cones cannot rub, because a bruised cone seats on a high point and shows a gap at the edge of the seat.
Three assemblies where a flush head and a drive that will not cam out are both required:
| Where it sits | The screw fixes a hinge, a bracket or a connector into a board or a panel where the head has to be flush and the joint is driven at speed on a line. |
| When it goes wrong | A Phillips recess that cams out deforms the cross and the screw cannot be re-driven, and a head above the surface shows on the finished furniture. |
| Why it happens | The boards are pre-drilled, the screws are driven with a clutch driver, and the joint is assembled once. |
| What we control | Recess checked with a PZ bit, thread matched to the board, and the first article driven at the line torque. |
| Where it sits | The screw closes a socket plate, a switch box or an appliance cover where the nickel finish has to match the visible hardware and the head must sit flush. |
| When it goes wrong | A plated recess that flakes at the ribs leaves a bright spot, and a loose cover on an accessory plate is a safety issue. |
| Why it happens | The parts are visible, the joint is serviced, and the screws are driven by hand or with a low-torque driver. |
| What we control | Recess and cone checked after plating, thread gauged, and the first article assembled in a sample plate. |
| Where it sits | The screw joins a cover to a chassis or a boss where a pilot hole has been prepared and the head countersinks into the panel. |
| When it goes wrong | A blunt point in an undersized pilot splits a moulded boss, and a thread that is too coarse strips the sheet before the head seats. |
| Why it happens | The pilot is pre-drilled or cored, the sheet is thin, and the joint may be opened for service. |
| What we control | Thread pitch and pilot size matched on the drawing, and the first article driven into a sample of the same material. |
Four reasons that matter on a countersunk Pozi screw, each tied to what the drawing has to prove:
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Seat, recess and plating reviewed together
The countersink angle, the Pozi recess size and the plating thickness are reviewed before tooling, so a head that would stand proud or a recess that would not take the bit is raised first. Basis: Seat, recess and coating reviewed before tooling. |
Head, ribs and thread in one route
The cone and the full Pozi recess, ribs included, are formed in one heading operation, and the thread is rolled before plating. Basis: One route from wire to plated screw. |
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Recess driven and thread gauged after plating
The recess is driven with a PZ bit and the thread is gauged in its plated condition, on the first article. Basis: First article checked with the PZ bit. |
First article to repeat production
The first article fixes the drawing revision, wire heat, die set, thread roll and plating batch; repeat orders are compared against that record. Basis: First article signed off before the batch is released. |
Shi Shi Tong forms these CSK Pozi screws on a heading machine that upsets the 90° cone and the Pozi recess in one operation, then rolls the self-tapping thread with a blunt point and applies the nickel plating. The first part of every run is measured on the head and the recess, driven with the PZ bit and gauged after plating, before the batch continues.
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Between runs the insert is changed to the drawing cone and recess, and the thread rolls to the pitch; the first part goes to the projector, to the PZ bit and to the gauges. The plating batch is recorded with the parts, so a repeat order can be compared against the coat thickness as well as the dimensions.
What decides whether a pozi countersunk screw passes is the head diameter and angle, the Pozi recess size and depth, the thread class after plating and the finish itself. The inspection agreement covers those, and the criteria come from the drawing.
Head angle and recess on the projector |
Thread gauged after plating |
Hardness testing against the property class |
Salt-spray testing of the plated part |
Each CSK Pozi screw batch is recorded against the drawing revision: head and recess from the first article, the thread gauged after plating, and the bit size carried on the label. If the PZ bit check fails, the parts back to the last good setting are held and re-checked.
If the finish needs an independent report, it is planned with the batch so the paperwork and the parts ship together under one batch number.
Every shipment of CSK Pozi screws is traceable to the wire it was made from. The grade, heat number and property class 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 material or the finish. The documents carry the drawing revision and the batch number, so the paperwork can be matched to the parts.
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 plated parts the first article is driven at the joint torque with the bit the customer uses, so the recess and the plated thread are signed off together. Buyers visit during the process to review samples and to see how the heads and the plating line run.
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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 header 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 |
It is a countersunk (CSK) self-tapping screw with a Pozidriv recess. This one is carbon steel, nickel plated, with a flat head, a blunt point and a thread that forms its own grip in a pilot hole.
No. A Pozi bit has four additional ribs that a Phillips bit does not, and a Phillips bit will start in a Pozi recess without engaging them. The screw then drives part way and cams out exactly as a Phillips would.
Because it holds torque better. The ribs spread the load, so the recess deforms later and the bit stays in the head under a power driver — fewer damaged heads and less rework on a line.
Yes, with a pilot hole. The blunt point suits a drilled or punched hole in sheet, or a cored hole in a moulded boss; it is not intended to start its own hole in solid material.
It does, slightly. Nickel adds a few microns, most of it in the corners of the cross, so the recess is driven with the PZ bit after plating and the thread is gauged in the plated condition.
Head diameter and angle, Pozi recess size and depth, thread form and pitch, point form, length and datum, material and property class, finish and coating thickness, and the pilot hole size.
How a CSK Pozi screw project runs from drawing to repeat delivery:
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1
Send the drawing or sample
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→ |
2
Seat, recess and coating review
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→ |
3
First article with the PZ bit
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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 angle, Pozi recess size and depth, thread form and pitch, point form, length and its datum, material and property class, finish, and the pilot hole size.
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Head diameter and angle
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Pozi recess size
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Thread form and pitch
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Point form
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Length and datum
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Material, class and 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
