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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:8 Inch Long Screws Pan Head Cross Recessed
Materials:Steel
Surface treatment:Nickel Plated
Head Type:Pan Head
Drive:Phillips (cross)
Thread:Machine thread, half thread
Point:Blunt
Forming:Two-die heading
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M14
Number:84
We make long pan head screws in nickel plated carbon steel with a Phillips recess and a half thread, quoting them from M1 to M14; eight inches is about 203 mm. Head, recess, both lengths and plating come from your drawing, and the first article is assembled through your joint.
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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.
These are long pan head screws in nickel plated carbon steel with a Phillips recess and a half thread, quoted from M1 to M14 with Number 84. Eight inches is about 203 mm: the length is the defining dimension, and everything about the part — the drive, the thread position and the packing — follows from it.
Pan head. A low dome on a bearing ring, so the clamp is spread without a separate washer.
Half thread. The plain shank runs through the joint and the thread engages only at the far end.
Long shank. A slender body that passes through the assembly and sets the distance between its parts.
Nickel plating. A bright barrier deposit over carbon steel, suitable for visible indoor work.
Long pan head screws with a half thread are used where a joint is deep, the head is visible and the drive has to be a bit: display frames, tall stand-offs, furniture members that cannot be reached with a wrench.
At eight inches a screw stops behaving like a fastener and starts behaving like a rod. The shank has enough length to twist under the driver, enough spring to store torque, and enough mass to bend if it is handled carelessly. That changes the order of the design decisions: the drive and the thread position come first, and the head is chosen last.
Driving is the first consequence. A Phillips recess in a pan head is a shallow drive, and on a long shank part of what the driver applies is absorbed before the thread turns. The result is that the screw has to be driven steadily, with a bit that fits and a pilot or thread that runs freely; a driver with more power does not help once the recess is slipping.
The half thread is the second consequence. On a long pan head screw the plain section is most of the length, and it is what passes through the clearance holes of the joint. The thread at the far end does the clamping, and the position of the thread start is quoted from the tip rather than left to subtraction, because on an eight inch part a centimetre either way changes the joint.
Packing is the third, and it is the one customers do not think about until parts arrive bent. A long screw loaded at both ends in a crate takes a set, and the measurement that matters is the one along the whole length; the parts are supported through the route and packed so the length is not loaded, which is a process decision rather than a specification.
Nickel plating is the finish around all of it. It is a barrier deposit rather than a sacrificial one, bright and hard, and it suits a long screw that is visible: the head and the shank look the same along their length, and the deposit is thin enough to keep the thread usable.
The recorded range is M1 to M14, with lengths made to the drawing; eight inches is about 203 mm. Custom lengths up to 2,000 mm are subject to DFM review after drawing submission. For long pan head screws the quotation carries head diameter and height, recess depth, overall length, thread length and the plating.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Pan head, Phillips | Head diameter, height and recess depth |
| Shank | Plain section through the joint | Diameter and length |
| Thread | Half thread at the tip | Thread length, pitch and gauging |
| Plating | Nickel over carbon steel | Thickness and gauging after plating |
| Material | Carbon steel | Grade and heat number on the certificate |
| Packing | Support along the length | Agreed with the first article |
Thread length and plain length are quoted separately. On a long pan head screw the division is the joint: a thread that starts too early grips the stack, and one that starts too late does not reach far enough into the far part.
Overall length is the dimension that arrives bent. It is worth a tolerance of its own on an eight inch part, because a shank that is straight to the eye can still be outside a tight overall length after handling.
Three features define the part: the long shank, the half thread and the nickel finish. The first gives the reach, the second keeps the joint clamped rather than threaded, and the third makes the part presentable.
| Feature | What it gives | What it costs |
|---|---|---|
| Long shank | Reaches through a deep assembly | Twists and springs under torque |
| Half thread | Thread only where it works | Both lengths must be specified |
| Pan head | Load spread without a washer | Stands above the surface |
| Phillips recess | Fast drive with a common bit | Shallow drive on a long shank |
| Nickel plating | Bright barrier finish indoors | Build in the recess and thread |
The length is the reason the part is bought. A joint that spans eight inches cannot be closed by a standard screw and a nut, and a long pan head screw reaches from the outer face to the tapped part without a spacer.
The cost is that the screw is a spring. On a long shank the torque arrives late and unevenly, so the joint is tightened in stages or with a driver that can measure, and the thread is made to run freely so the shank is not fighting it.
The recorded finish is nickel plating over carbon steel. Nickel is a barrier deposit: it protects by keeping the steel away from the atmosphere rather than by sacrificing itself, so it is bright and hard and it holds its appearance on a screw that is visible along its length.
| Option | How it protects | Effect on shank and head | Typical use |
|---|---|---|---|
| Nickel plated | Barrier deposit, bright | Thin build; recess and thread re-checked | Visible indoor assemblies |
| White zinc plated | Sacrificial zinc | Thin build; wears at the shank | General indoor work |
| Black zinc plated | Sacrificial zinc, dark | Thin build; wear visible | Dark housings |
| Dacromet | Inorganic zinc-aluminium layer | Thick; thread allowances needed | Wet and outdoor assemblies |
| Stainless alternative | Passive film, no build | Shank and thread as made | Wet and food service |
Where the joint is damp, nickel is the wrong answer: it is a barrier, so a scratch in the coating is a rust point, and on a long screw the shank is scratched where it passes through holes. A sacrificial coating or a stainless body is the specification for anything wet.
Where the joint is dry and visible, nickel is the best of the inexpensive finishes. It keeps the head and the exposed shank looking alike, which on a long screw is more noticeable than on a short one.
Three assemblies where these long pan head screws are the fixing:
| Where it sits | The screw runs from the outer face of a frame to a tapped part at the back, where the length is set by the depth of the assembly. |
| When it goes wrong | A thread that starts too early grips the frame, and the joint never closes. |
| Why it happens | The joint is deep, the head is visible, and the far part is tapped. |
| What we control | Thread start and overall length checked; first article assembled. |
| Where it sits | The screw holds a panel at a stand-off from a backing frame, where the fixing is visible and has to look finished. |
| When it goes wrong | The plating marks at the shank where it passes the panel, and the length shows it. |
| Why it happens | The joint is visible, it spans a gap, and the finish is part of the product. |
| What we control | Coating checked; first article assembled and inspected. |
| Where it sits | The screw joins a long member to a bracket where a wrench cannot reach and the drive has to be a driver. |
| When it goes wrong | A long shank twists before the thread seats, and the joint stays loose. |
| Why it happens | The joint is long, the access is from one side, and the drive is a bit. |
| What we control | Shank and thread checked; driving tested on the first article. |
Four reasons that matter on a very long part, each tied to what the drawing has to prove:
|
Thread position and length agreed
Thread length from the tip, plain length from the head, overall length and recess depth are agreed as a set, because on long pan head screws the division is the joint. Basis: Thread position and length agreed. |
Two-die heading for long blanks
A two-die header supports the blank while the head is formed, then the half thread is rolled and the parts nickel plated within one route. Basis: Two-die heading for long blanks. |
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Length and shank checked
The overall length and the shank are checked along the part, because a long screw can measure correctly at both ends and still not pass the joint. Basis: Length and shank checked. |
Packing fixed by the first article
Packing is agreed with the first article, because on an eight inch part the transit is part of the process. Basis: Packing agreed at first article. |
Shi Shi Tong makes these long screws on two-die headers that form the pan head and cut the Phillips recess, then draw the long shank, roll the half thread at the tip and nickel plate the parts. The first part of every run is measured on head diameter and height, recess depth, overall length and thread before the batch continues.
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An eight inch blank is the hardest thing on a heading line. It has to be held over most of its length while the head is formed at one end, and any misalignment in the grip shows as a head that runs off the axis; the screw then measures correctly and will not pass a close hole.
What decides whether these long pan head screws pass is the head, the thread, the overall length and the plating. The inspection agreement covers those, and the criteria come from the drawing.
Head and thread start on the projector |
Thread gauged after plating |
Hardness checked on the wire |
Coating proved by salt spray |
The head is checked for diameter, height and recess depth, the thread start position measured from the tip, and the overall length checked on the finished part. The thread is gauged after plating, and the coating is checked for thickness in the recess.
The first article is assembled through the customer joint. A long screw that threads correctly in a gauge and will not pass the stack is still a part that fails, and only the assembly shows it.
Every shipment of these long 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 coating. The documents carry the drawing revision and the batch number, so a repeat order keeps the same lengths and plating.
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 long pan head screws the first article is assembled through the customer joint, because the plain length is what the joint feels. Buyers visit during the process to review samples.
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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 two-die 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 plain shank passes through the joint and the thread engages at the far end, so the parts are clamped rather than threaded.
About 203 mm. The thread sizes in this family are metric, from M1 to M14.
The shank twists under torque, so the thread turns less than the driver. Steady driving and a clean thread matter more than force.
It is a barrier deposit, so a scratch is a rust point. For wet joints a sacrificial coating or stainless is the right choice.
Thread length from the tip and plain length from the head, both quoted separately.
Head diameter and height, recess depth, overall length, thread length, the grade and the plating.
How a long pan head screw project runs from drawing to repeat delivery:
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1
Send the drawing and the joint it spans
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→ |
2
Thread position, lengths and plating agreed
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→ |
3
First article assembled through your joint
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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, recess depth, overall length, thread length, the grade and the plating.
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Head diameter
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Head height
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Overall length
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Thread length
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Grade
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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
