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+86 13143444311
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:Pan Head Self Tapping Screws, Phillips Pan Head Screw
Materials:304 Stainless Steel
Surface treatment:Plain
Head Type:Pan head
Drive:Phillips cross recess
Thread:Self-tapping (spaced thread)
Point:Sharp, tapered
Forming:Single Die Heading
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10
We make pan head self tapping screws in 304 stainless steel, quoting them from M1 to M10 with lengths made to the drawing. The point form, thread spacing and pilot hole are agreed as one set, and the first article is driven into your own material and hole.
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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.
Pan head self tapping screws are screws with a rounded head, a wide bearing face, a cross recess and a spaced thread with a sharp point that forms its own path. The part recorded here is 304 stainless, plain finish, quoted from M1 to M10 with lengths made to the drawing.
Pan head. A domed top over a wide bearing face that sits on the surface and spreads the clamp.
Cross recess. Four tapered arms driven by a matching bit, sized as a PH number.
Self-tapping thread. A wide-pitched thread that cuts or forms a thread in the material as it is driven.
Sharp point. A tapered point that starts in a pilot hole and opens it as the thread engages.
They are used on sheet metal covers, plastic housings, brackets and electrical boxes, where the joint is assembled in one motion and the fixing has to hold without a nut behind the panel.
A self-tapping joint is decided by two diameters: the screw’s thread and the hole it goes into. The thread does not create its own material, it moves it. If the hole is too small, that material has nowhere to go and the panel bulges or splits; if the hole is too large, the thread cannot reach enough material and the joint strips before the head seats.
The window between those two failures is narrow, and it moves with the material. In sheet metal the hole is set so the thread cuts and leaves a full turn of engagement; in plastic the hole is set so the thread forms a thread and the boss takes the stress without splitting. Stainless makes the window narrower still, because it work-hardens as it is displaced: a hole that is slightly small does not just bulge, it hardens the material around the hole and the screw stalls.
The point form is part of the same decision. A sharp point starts and opens the hole, so it tolerates a tighter pilot; a blunt point relies on the hole already being right and forms the thread without piercing. Choosing the point after choosing the hole, or the other way round, is the usual source of a joint that works on the bench and fails on the line.
The head then does the last part. Once the thread has reached its limit, the clamp is carried by the bearing face on the surface, and a wide pan head spreads it so the material around the hole does not yield. That is why a pan head is paired with self-tapping threads so often: it takes over exactly where the thread runs out of strength.
None of this is visible after assembly. A joint with the wrong pilot hole looks identical to one with the right one, until it is loaded or opened, which is why the hole belongs on the drawing and on the first article rather than in a note about the process.
The recorded range is M1 to M10, with lengths made to the drawing. Custom lengths up to 2,000 mm are subject to the drawing submission and DFM review. The quotation for pan head self tapping screws carries the head diameter and height, the PH size and recess depth, the thread pitch and spacing, the point form and the overall length.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Pan head, on the surface | Diameter, height and bearing face |
| Recess | Phillips, PH size per diameter | Arm depth and floor thickness |
| Thread | Self-tapping, spaced | Pitch, spacing and engagement length |
| Point | Sharp tapered or blunt | Point angle and length |
| Pilot hole | Set by the material, on the mating drawing | Agreed with the first article |
| Length | Overall, head included | Length tolerance and thread start |
Thread pitch and spacing are quoted as a pair, because a self-tapping thread is defined by both. Two parts with the same pitch and a different spacing behave differently in the same hole, which is why the spacing is measured rather than assumed.
Point length matters as much as point angle. A long point reduces the thread length available for engagement; on a thin panel that can mean only a turn or two of thread doing all the work, and that is the joint that strips.
Length is measured over the head. On a joint through a panel into a bracket, the usable engagement is the overall length minus the panel thickness, and that is the number to check against the pilot hole depth.
Four properties decide pan head self tapping screws, and each one carries a cost:
| Property | What it gives | What it costs |
|---|---|---|
| Self-tapping thread | No tapping, no nut | The pilot hole becomes critical |
| Sharp point | Starts and opens a hole | Can pierce the part behind the panel |
| Pan head | Wide bearing face for the clamp | Stands above the surface |
| 304 stainless | Corrosion without a coating | Work-hardens; narrower hole window |
The value is a joint that assembles in one operation and holds in materials that cannot be tapped. That is why the form is everywhere in sheet metal and plastics: nothing has to be prepared beyond a hole.
The cost is that the hole is now part of the fastener’s specification. A supplier can deliver a perfect screw and the joint will still fail if the hole is wrong, and the hole is usually made by someone else.
The recorded finish is plain over 304 stainless. The alloy carries the corrosion resistance, and passivation restores the oxide layer after heading and rolling, which matters because the thread and point are cut features with fine edges.
| Option | How it protects | Effect on head and recess | Typical use |
|---|---|---|---|
| Passivated, plain | Removes free iron; rebuilds oxide | No build; recess as cut | Default for stainless |
| Electropolished | Levels the surface | Edges rounded slightly | Food and medical equipment |
| Black oxide on stainless | Colours the surface | Thin film; fit unchanged | Dark housings |
| Clear zinc on steel | Sacrificial zinc | Build in recess; re-checked | Hidden indoor joints |
| Zinc flake on steel | Lamellar coating | No acid bath; edges covered | High-volume panels |
On a self-tapping part the thread crest and the point are the thinnest, most stressed features, and they are also where a coating wears off first. That is why stainless is often chosen for a joint that is opened: there is no layer to lose at the point.
Where a zinc finish is used instead, the recess is gauged after plating and the point is inspected for a coating that has bridged the sharp edge. A bridged point does not start cleanly, and in a thin panel that is the difference between a seated screw and a torn hole.
Three settings where a pan head and a self-tapping thread are the standard joint:
| Where it sits | The screw closes two formed sheets where the head has to spread the load and the joint is repeated many times. |
| When it goes wrong | The pilot hole is slightly small and the sheets bulge between fixings. |
| Why it happens | The metal is thin, the holes are punched, and the joint is assembled at speed. |
| What we control | Point and pitch proved in the customer sheet; first article checked for bulge. |
| Where it sits | The screw forms a thread in a moulded boss and the pan head spreads the load on the flange. |
| When it goes wrong | The boss splits at the thread start, or the joint strips before the head seats. |
| Why it happens | The material is plastic, the boss is moulded, and the joint is opened once. |
| What we control | Pitch and point proved on a sample moulding; first article driven and removed. |
| Where it sits | The screw fixes a lid or a bracket where the head is visible and the fixing must not rust. |
| When it goes wrong | A plated screw corrodes at the head and stains the box. |
| Why it happens | The enclosure is indoors but sometimes damp, and the fixing is serviced. |
| What we control | Grade and passivation confirmed; first article fitted in the box. |
Four reasons that matter on a joint decided by a hole, each tied to something the first article has to prove:
|
Point, pitch and hole agreed together
The point form, the thread spacing and the pilot hole are settled as one set, because a thread that suits one hole will bulge or strip in the next. Basis: Point, pitch and hole together. |
Headed, recessed, threaded, passivated
The pan head and cross are formed in one stroke, the self-tapping thread rolled with the point, and the batch passivated after forming. Basis: One route from wire to part. |
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Thread and point measured, then driven
The thread spacing and the point are measured against the agreed profile and then proved by driving into the customer material, because only the drive shows whether the joint holds. Basis: Measured, then driven in your panel. |
Same thread, same hole
The rolling dies and the point tool are recorded with the drawing revision, so a repeat order works in the same pilot hole without changing the process. Basis: Same thread across orders. |
These screws are headed on single-die machines that form the pan head in one stroke, cut with the cross recess, thread rolled with the self-tapping profile and the point formed, then passivated as a batch. The first part of every run is measured on head diameter and height, recess depth, thread spacing, point and length.
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Rolling the self-tapping thread is where the part is decided. The blank diameter is set so the rolls displace the material into the thread form rather than squeezing it, and the rolls are kept clean: a smeared crest cuts badly in sheet and tears in plastic. On stainless the same setting also has to avoid work-hardening the crest into something brittle.
The point is formed in the same operation and its length is what allows the screw to start before the thread bites. A point that is a little short makes the screw walk on the panel; a point that is long eats into the thread length, and on thin material that is engagement lost from the part that matters.
Passivation follows forming and is checked on the point and the recess. Both are cut features with fine edges that hold contamination, and both are invisible once the joint is closed.
What decides whether pan head self tapping screws pass is the thread, the point, the head and the surface. The inspection agreement covers those, and the criteria come from the drawing.
Head and recess on the projector |
Thread spacing and point checked |
Hardness against the 304 spec |
Salt-spray testing of point and recess |
Thread spacing, thread length and point angle are measured against the agreed profile, together with head diameter and height and recess depth. The measurements are recorded per batch, so a shift in the rolling dies is caught before it reaches the line.
The functional check is a drive into the customer material, at the line torque, with the hole the customer uses. A sample from every batch is driven and removed, then the hole and the surrounding material are inspected for tearing, bulging or a thread that has not fully formed.
Corrosion is checked on the point and the recess in the salt-spray chamber. Those are the two places a passivation problem shows, and both are hidden once the joint is assembled.
Every batch is traceable to the heat of stainless it was made from. 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 including the point form and thread spacing, and the passivation records for the batch. The documents carry the drawing revision and the batch number, so a repeat order of pan head self tapping screws works in the same hole.
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 self-tapping joint the first article is driven into the customer material with the customer hole, because that is the only place the joint is decided. Buyers visit during the process to review samples.
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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, the thread rolling station and the passivation 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 depends on the material and the thread. It is agreed with the first article and written on the mating drawing, because it decides whether the joint holds.
The material has nowhere to go, so the panel bulges or splits. In stainless the surrounding material also work-hardens and the screw can stall.
The thread cannot reach enough material and the joint strips before the head seats, which shows as a screw that turns without pulling down.
A blunt point in a moulded boss, where the thread forms without piercing the far side. A sharp point suits sheet and through holes.
It work-hardens as it cuts, so the hole window is narrower and the tooling has to be sharper. In return the joint does not rust.
Head diameter and height, PH size, thread pitch and spacing, point form, overall length and the pilot hole.
How a pan head self tapping project runs from drawing to repeat delivery:
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1
Send the drawing and the pilot hole
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→ |
2
Point, pitch and hole agreed
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→ |
3
First article driven in your material
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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, PH size, thread pitch and spacing, point form, overall length and the pilot hole.
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Head diameter
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PH size
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Thread pitch
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Point form
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Pilot hole
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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
