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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:Pan Washer Head Machine Screw
Materials:Steel
Surface treatment:Nickel Plated
Head Type:Pan Washer Head
Drive:Phillips
Thread:Machine Thread
Point:Blunt
Forming:Single Die Heading
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M14
Number:779
We make pan washer head machine screws in nickel plated carbon steel with a stepped washer face, a cross recess and a machine thread, quoting them from M1 to M14. Face diameter and thickness, recess, thread and plating come from your drawing, and the face is checked flat after plating rather than before.
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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 pan washer head machine screw has a pan dome on a wide washer face and a machine thread that runs into a tapped hole or a nut. The recorded item is nickel plated carbon steel with a pan washer head, quoted from M1 to M14 with Number 779.
Washer head. A pan dome on a flat annular face with a step at its outer edge. The face is formed with the head, so it cannot be left off, and it is the surface that bears on the part.
Machine thread. A rolled thread with a blunt chamfered end, made for a tapped hole or a nut. The clamp load comes from the thread, which is what separates this part from a tapping screw with the same head.
Nickel plate. A hard barrier deposit, bright and even on a wide face. It does not sacrifice itself the way zinc does; it protects by keeping the atmosphere off the steel, and it shows a uniform tone across an annulus.
On a washer head the bearing face is a ring: an annulus between the hole and the outer edge of the flange. The clamp load from the machine thread arrives at the inner diameter and leaves through the ring, so the pressure is highest at the inner edge and falls towards the outer one. The head is designed around that gradient, and a face that is not flat turns the ring into a line.
Nickel plating interacts with that ring in a way a coating on a pan head does not. Barrel plating builds slightly thicker at edges and corners, so the outer rim of the face and the step are the first places to grow; on a wide ring a few microns at the rim is enough to make the head touch at its outer edge before the rest of the face arrives. The joint then reads as tight while it is only the edge that has loaded.
That is why the face is checked flat after plating rather than before, and why the plating range is treated as a working tolerance. On a washer head the visible surface and the functional surface are the same annulus, so a plating variation is both a look and a fit.
The head form follows the JIS pan washer head, which sets the relationship between the face diameter and the head height. That relationship is what makes the face wide enough to spread load without making the head so tall that it fouls a cover; a different standard would give a different ring, and the drawing names the one it follows.
The machine thread is what the joint is actually rated on. The head does not add clamp load; it only delivers what the thread generates onto the ring without marking the part, which is why a washer head with a coarse thread and a thin panel is a poor pairing and a washer head with a fine thread and a machined face is a good one.
The family is quoted from M1 to M14, with M1, M2, M3, M4, M5, M6, M7, M8, M9, M10 and M14 in the recorded range. Custom lengths up to 2,000 mm are subject to DFM review after drawing submission; on pan washer head machine screws the face diameter and thickness are quoted with the head height, because together they define the ring.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Pan washer head, stepped face | Face diameter, thickness and flatness |
| Recess | Phillips cross | Depth and width, bit tried after plating |
| Thread | Machine thread | Pitch and length, gauged per batch |
| End | Blunt, chamfered | Chamfer cut, not deburred |
| Plating | Nickel, bright | Thickness range and face flatness after plating |
| Length | From under the washer face to the end | Measured on the shop plate |
The face diameter is chosen from the part it bears on, not from the thread. On a soft or coated surface a wider ring spreads the load below the coating’s yield; on a machined face a smaller ring keeps the footprint tidy. The drawing quotes the diameter for that reason, and the head is not left to a standard.
Length is measured from under the washer face, because that is what touches the part. Measuring from the top of the dome would hide the face thickness inside the thread length, and on a screw that has to engage a shallow tapped hole that thickness is the difference between full engagement and none.
Three features define this part: the washer face, the machine thread and the nickel plate. The first spreads the load, the second clamps, and the third keeps a wide visible surface even.
| Feature | What it gives | What it costs |
|---|---|---|
| Washer face | A defined bearing ring without a loose washer | A step that can roll over in a worn die |
| Machine thread | Removable, repeatable clamp load | Needs a tapped hole or a nut |
| Nickel plate | Bright, hard, even on a wide face | Barrier only; a scratch exposes steel |
| Stepped head | A crisp outer edge and a flat ring | Less head height for the recess |
| Blunt end | Runs into an existing thread | Chamfer cut, not deburred |
The washer face replaces a loose washer, and on a line that is worth something: no bin, no pick, no joint that goes out without one. What it cannot do is move, which on an uneven surface a loose washer can, and what it cannot do either is be replaced when it dishes. That is why the face thickness is quoted: it is the part that has to resist dishing.
Nickel is chosen here for the look as much as for the protection. A washer head presents a large flat annulus, and a zinc deposit on a surface that size shows grain and patchiness that a small head would hide. Nickel levels better, and on a visible joint that is what the customer is buying.
The recorded finish is bright nickel. It is a barrier deposit: hard, bright and even, and it protects as long as it is intact rather than by corroding in place. On a washer head the annulus is the surface that matters, and an even deposit is what keeps the ring flat.
| Finish | How it protects | Effect on face and recess | Typical use |
|---|---|---|---|
| Bright nickel | Hard barrier deposit | A few microns; face re-checked | Visible panels and covers |
| White zinc | Sacrificial zinc | A few microns; re-checked | General indoor work |
| Black nickel | Dark nickel deposit | A few microns; re-checked | Dark visible equipment |
| Black oxide | Thin conversion film, oiled | No measurable build | Unseen joints |
| Dacromet | Zinc-aluminium flake layer | Film builds; face re-checked | Outdoor and wet service |
The limit of nickel is what happens when it breaks. A slipped driver, a ding at the rim or a scratch across the face exposes steel, and there is no zinc around the damage to corrode first. On a wet joint that is a pitting site in the middle of a visible surface, which is why nickel is the wrong finish for washdown even though it looks right in a sample.
Where the joint is exposed, the answer is stainless or a flake coating rather than a thicker nickel. The second point is that plating changes the face, so the first article is checked for flatness after plating and the recess is driven with the production bit in the same condition.
Three assemblies where a pan washer head machine screw is the fixing:
| Where it sits | The screw fixes a panel or a bracket where the head is visible on a painted face and the washer ring protects the coating. |
| When it goes wrong | A narrow head cracks the paint around the hole, and an uneven face bears on a ring and marks the panel. |
| Why it happens | The panel is coated, the head is visible, and the joint is serviced. |
| What we control | Face flatness after plating checked, recess driven with the production bit. |
| Where it sits | The screw closes a cover or fixes a plate on a machined or coated face where the load has to be spread without a washer on the line. |
| When it goes wrong | A loose washer is dropped inside the enclosure, and a head that rocks leaves a gap in a gasketed joint. |
| Why it happens | The joint may be gasketed, the fixing repeats, and the cover is serviced. |
| What we control | Face diameter and flatness checked, thread gauged per batch. |
| Where it sits | The screw joins a bracket or a fitting into a tapped insert where the material under the head is soft and the head shows. |
| When it goes wrong | A small head compresses the substrate, and a bright zinc face reads as a different tone to the rest of the hardware. |
| Why it happens | The material is soft, the head is seen, and the assembly is made once. |
| What we control | Face flatness and tone held to the sample, thread checked. |
Four reasons that matter on a wide plated face, each tied to what the drawing has to prove:
|
Face and plating reviewed together
The face diameter and thickness, the plating build and the part it bears on are reviewed as one set, so a ring that would dish or a face that would touch at the rim is raised before the die is cut. Basis: Face and plating reviewed as one set. |
Heading, stepping and plating in one route
The pan dome, the stepped face and the cross are formed in one stroke, the thread is rolled and the parts are nickel plated and baked in the same route. Basis: One route from wire to plated screw. |
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Face read after plating
The face is checked for diameter, thickness and flatness after plating, and the recess is driven with the production bit in the same condition. Basis: First article checked after plating. |
First article fixes the setting
The first article fixes the wire heat, the die set, the roll and the plating barrel; repeat orders are compared against that record. Basis: First article signed off before the batch is released. |
Shi Shi Tong forms these pan washer head machine screws from carbon steel wire on single-die headers that upset the pan dome and the stepped washer face and form the cross in one stroke, rolls the machine thread to a blunt chamfered end and nickel plates the parts. The first part of every run is measured on the face, driven with the production bit and checked for flatness before the batch continues.
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The step between the face and the dome is the feature that a worn die loses first. Formed sharp it leaves a crisp bearing ring; formed rounded it is a radius, and a rounded step is no longer a step, so the effective face shrinks back towards a pan head. The step is checked on the section of the first article and the face is measured across it.
What decides whether pan washer head machine screws pass is the face, the step, the recess, the thread and the plating. The inspection agreement covers those, and the criteria come from the drawing.
Face diameter and step on the projector |
Thread gauged after plating |
Hardness testing against the property class |
Salt-spray testing of the nickel plate |
The face is checked for outside diameter, thickness and flatness at the rim and at the step, and the step itself is checked on the section. Flatness at the rim is the reading that matters on a plated part, because that is where the deposit is thickest and where the head first touches.
The recess is driven with the production bit in the plated condition, and the thread is gauged after plating. On a washer head the plating on the face and in the cross is applied in the same bath, so both are read as delivered rather than as formed.
Every shipment of pan washer 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 material or the plating. 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 a wide plated face the first article is also the tone sample, since the whole annulus is visible at once. Buyers visit during the process to review samples and to see how the heads are formed and plated.
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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 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 |
It spreads the clamp load over an annulus instead of a dome tip, without a loose washer. The load is highest at the inner edge and falls towards the rim.
Yes. A deposit builds thicker at the rim, so the head can touch at its outer edge first. The face is checked flat after plating, not before.
It is harder, brighter and levels better on a wide flat face. It is a barrier rather than a sacrificial coating, so a scratch exposes steel.
Yes, and that is the point. What it cannot do is move on an uneven surface, or be replaced when it dishes.
The drawing names it; this family follows the JIS pan washer head, which sets the face diameter against the head height.
Face diameter and thickness, head height, recess size, thread size and length, length under the face, and the plating build.
How a pan washer head machine screw project runs from drawing to repeat delivery:
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1
Send the drawing or the panel sample
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2
Face, recess and thread review
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3
First article checked after plating
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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 face diameter and thickness, the head height, the recess size, the thread size and length, the length under the face and the plating build.
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Face diameter
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Face thickness
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Head height
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Recess size
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Thread and length
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Plating
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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
