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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:Metric Pan Head Machine Screws Fasteners
Materials:Carbon Steel
Surface treatment:Nickel Plated
Head Type:Pan Head
Drive:Phillips cross recess (PH)
Thread:Metric machine thread
Point:Plain, chamfered
Forming:Single Die Heading
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10
We make metric pan head machine screws in carbon steel with a nickel plate, to a stated standard series, quoting them from M1 to M10. Series, head diameter and height, PH size and thread come from your drawing, and the first article is fitted in your own panel.
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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.
Metric pan head machine screws are machine screws with a rounded head, a wide bearing face and a cross recess, made to a metric standard series. The part recorded here is carbon steel with a nickel plate, quoted from M1 to M10.
Pan head. A domed top over a wide, slightly dished bearing face that sits on the surface rather than in it.
Phillips recess. Four tapered arms, sized as a PH number that follows the screw diameter.
Machine thread. A uniform metric thread for a tapped hole, a nut or an insert.
Nickel plate. A thin, hard, bright deposit that keeps the cross crisp and the head bright.
Metric pan head machine screws are the default fastener for covers, brackets, plates and equipment panels: they close a joint on the surface, spread the clamp, and are driven with the most common bit on any bench.
The pan head spreads the clamp over a bearing face wider than the thread it carries.
A pan head is not one geometry. The Japanese, the German and the Chinese standard series each define a pan head machine screw, and their head diameters and head heights are close but not identical at the same thread. A screw made to one series will fit a countersink-free hole made for another, because the head sits on the surface — but it will not match the head dimension the drawing states, and a row of mixed parts shows it.
That is why this page names the series it is made to. Where a drawing simply says “pan head machine screw” without a standard, the supplier picks one, and the part that arrives may be a little flatter or a little wider than the panel was designed around. Naming the series removes the choice.
The recess carries the same issue in a different way. The PH number follows the diameter, but the depth available for it depends on head height, and head height varies between the series; two screws of the same M3 diameter can therefore take the same bit and drive very differently.
The thread itself is the least variable part. A metric machine thread at M3 is M3, and the joint is designed around that: the pitch, the tapped hole and the nut are all standard. What changes between suppliers is the head and the recess, so those are the features to control when a series is specified.
Nickel plating then sits on top of a geometry rather than changing it. It is thin and hard, so the head dimension and the cross depth survive plating, and the part stays bright indoors. The trade is the usual one: no sacrificial protection at a scratch, and galling in aluminium.
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 metric pan head machine screws the quotation carries the standard series, head diameter and height, the PH size and recess depth, thread pitch and overall length.
| Item | How it is defined | What we control |
|---|---|---|
| Standard series | JIS, DIN or GB | Head diameter and height to that series |
| Head | Pan, domed with a wide face | Diameter, height and bearing face flatness |
| Recess | Phillips, PH size per diameter | Arm depth and floor thickness |
| Thread | Metric machine thread | Pitch, length and start position |
| Length | Overall, head included | Length tolerance and thread start |
| Finish | Nickel plated | Thickness and recess re-gauged |
Head diameter is the dimension that decides whether a joint marks a soft panel, and it is exactly where the series differ. A drawing that gives neither a series nor a diameter leaves the most visible feature of the part to the supplier.
PH size is fixed by the diameter, but the recess depth is not: it is bounded by head height, which the series also sets. Both belong on the drawing, together with the series they are taken from.
Four features define the series, and each one is a trade:
| Feature | What it gives | What it costs |
|---|---|---|
| Standard series | Repeatable head dimensions | The drawing has to name the series |
| Pan bearing face | Clamp spread on panels | Stands above the surface |
| Phillips recess | Standard bit; torque release | Rounds when the bit is worn |
| Machine thread | Repeatable joint | Needs a tapped hole or a nut |
| Nickel plate | Hard, bright, crisp cross | No sacrificial protection at a scratch |
The value is predictability. A series gives a head diameter and height for every diameter in the range, so a panel designed around M3 accepts a replacement M3 from the same series and looks the same. That is what a standard is for, and it is why the series belongs on the drawing.
The cost is that the series is invisible in the part name. “Pan head machine screw” describes the form and not the geometry, so two suppliers can both be right and both deliver parts that do not match each other.
The recorded finish is nickel over carbon steel. On a metric pan head screw it keeps the cross at its cut depth and the dome at its cut diameter, so the series dimensions survive the finish, and it gives the bright appearance that a visible panel fixing needs.
| Option | How it protects | Effect on head and recess | Typical use |
|---|---|---|---|
| Nickel plated | Hard bright barrier | Thin build; recess as designed | Panels and instruments |
| Zinc plated | Sacrificial zinc | Slight build; recess re-checked | General indoor work |
| Colour zinc | Sacrificial zinc, thicker | Build measurable; recess gauged | Appliances and furniture |
| Black oxide | Conversion film, oiled | No measurable build | Dark equipment |
| Stainless, passivated | Passive film, no coating | Head and recess as formed | Wet and food areas |
Where the panel is finished and the head is seen, nickel is the finish that holds the appearance without a coating that dulls or fills the cross. Where the joint is damp, the answer is stainless rather than a thicker plate.
Where a zinc finish is used, the recess is gauged afterwards. A pan head has more depth to give than a countersunk head, but a heavy zinc layer still changes which bit seats.
Three assemblies where the standard series is the specification:
| Where it sits | The screw closes a panel where the head sits on painted sheet and the joint is serviced. |
| When it goes wrong | A mixed series is substituted and the row of heads no longer matches. |
| Why it happens | The panel is painted, the heads are visible, and the joint is opened. |
| What we control | Head diameter and height checked against the series; first article fitted. |
| Where it sits | The screw fixes a plate or a bracket where the head must clear a cover and the cross is driven by hand. |
| When it goes wrong | The cross rounds after a few services and the plate cannot be retightened. |
| Why it happens | The joint is small, the drive is a cross-tip, and the head is on the surface. |
| What we control | Recess proved with the bit; first article assembled and reopened. |
| Where it sits | The screw holds a bracket where the head is seen and the fixing comes out for delivery. |
| When it goes wrong | A head that is a little wider or flatter than the series reads as a different product. |
| Why it happens | The part is visible, the joint is assembled on site, and the finish must match. |
| What we control | Series dimensions and finish checked; first article fitted to a finished sample. |
Four reasons that matter on a standard-series screw, each tied to something the drawing has to prove:
|
Series named on the drawing
The standard series is agreed before quoting, because head diameter and height follow from it and they decide whether the part matches a panel designed around one series. Basis: Series named on the drawing. |
Headed, recessed and plated in one route
The pan head and cross are formed in one stroke, the thread rolled, and the parts nickel plated in the same sequence. Basis: One route from wire to plated screw. |
|
Head and recess measured to series
Head diameter and height are measured against the series and the cross is proved with the production bit, because both are what a replacement part has to match. Basis: Head and recess measured to the series. |
First article in your panel
The first article is fitted in the customer panel, because bearing pressure and appearance depend on the surface it presses on. Basis: First article fitted in the panel. |
These screws are headed on single-die machines that form the pan head and cut the cross recess in one stroke, rolled with the metric thread and nickel plated as a batch. The first part of every run is measured on head diameter and height, recess depth, thread and length, against the series the job is made to.
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|
Forming the pan head is a balance between diameter and height. The dome is pressed from the blank, so a head that is a little too wide comes out a little too thin at the rim, and the part still measures inside a loose tolerance while it no longer matches the head height the series states. That is why the series dimensions are checked together rather than separately.
Nickel plating is checked by measurement: the thickness on the batch, the recess re-gauged on plated parts, and the dome inspected for dulling. On a visible head the difference between bright and slightly milky is the difference between a part that reads as finished and one that reads as plated steel.
What decides whether metric pan head machine screws pass is the head, the recess, the thread and the plating. The inspection agreement covers those, and the criteria come from the drawing and the agreed series.
Head and recess on the projector |
Thread and start checked |
Core hardness checked |
Salt-spray testing of the nickel layer |
Head diameter and height are measured on a projector and compared with the series, the cross is measured and proved with the production bit, and the thread is gauged after plating. Length is measured over the head so the datum matches the drawing.
A sample from every batch is driven into the customer’s tapped part at the line torque and removed. That cycle shows a shallow cross or a soft arm, and on a standard series part it is the check that predicts whether a replacement screw will behave like the original.
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, including the series, and the plating thickness report. The documents carry the drawing revision and the batch number, so a repeat order keeps the same head and the same recess.
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 metric pan head machine screws the first article is fitted in the customer panel, because the series dimensions only matter in the surface they press on. Buyers visit during the process to review samples.
|
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 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 series is stated on the quote and on the inspection record. Where a drawing gives none, the head dimensions can differ from another supplier’s “pan head”.
Each series sets its own head diameter and height for a given thread, and the differences are small but visible in a row of heads.
The PH number that follows the diameter. The recess depth depends on head height, so the same bit can drive differently between series.
Less than a smaller head, because the bearing face is wide; a thin panel still benefits from a washer at high torque.
It resists wear and looks bright, but it does not protect a scratch. Outdoors a zinc finish or stainless is the better answer.
The standard series, head diameter and height, PH size, thread pitch and overall length.
How a metric pan head screw project runs from drawing to repeat delivery:
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1
Send the drawing and the series
|
→ |
2
Head dimensions and PH size agreed
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→ |
3
First article fitted in your panel
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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 standard series, head diameter and height, PH size, thread pitch and overall length.
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Standard series
|
Head diameter
|
Head height
|
|
PH size
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Thread pitch
|
Length
|
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
