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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:Metal Cutting Screws, Pan Head Thread Cutting Screws
Materials:Carbon Steel
Surface treatment:Nickel Plated
Head Type:Pan Head
Drive:Phillips cross recess
Thread:Coarse self-tapping thread, rolled, cut at the tip
Point:Blunt flat tip with cutting notches (thread-cutting)
Size:M1 - M14 (per drawing)
Forming:Single-die cold heading, thread rolled, nickel plated after notching
Number:734
We manufacture metal cutting screws: pan head Phillips screws with cutting notches in the tip that cut their own thread into a pilot hole in sheet, plastic or similar material. Notch form, tip, thread, length and pilot hole 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.
Metal cutting screws are thread-cutting screws: fasteners whose point carries cutting notches, so the thread is cut into a prepared hole instead of being forced into it. The recorded item on this page is a pan head Phillips screw in carbon steel with a nickel finish, a coarse rolled thread and a blunt flat tip with cutting notches, quoted from M1 per drawing with Number 734.
Cutting notches. Two or more flutes are formed into the tip of the thread. As the screw turns, the notches act as cutting edges and take a chip out of the hole wall, which is what separates a cutting screw from one that forms or rolls the material aside.
Blunt flat tip. The end is flat, not pointed, so the screw cannot drill its own hole. It goes into a pilot hole of the right size and cuts a thread in the wall of that hole.
Coarse thread, rolled. The thread is rolled on the shank and then cut at the tip to form the notches. Rolling gives a clean flank and work-hardens the steel, and the notch is what turns the flank into a cutting edge.
Pan head, Phillips. A low dome on a flat bearing ring with a cross recess, which is the standard drive for panel work: it centres, it takes a common bit, and it gives up before the head does.
Nickel plated. A bright, hard deposit on carbon steel. It protects the part and keeps the joint looking clean, and it is applied after the notches are cut so the cutting edges are finished and not bare.
The body is carbon steel wire, with grade and heat number on the batch record. The pan head and the Phillips recess are upset in one heading stroke, and the coarse thread is rolled up to the head.
The notches are cut into the tip after the thread is rolled. That order matters: cutting them before rolling would let the roll close them up, and the screw would arrive with flutes that look right and do not cut. The order of operations is what makes metal cutting screws reliable. On metal cutting screws the notch is the functional feature, so it is made last and checked first.
The tip is left blunt and flat, with the notches opening onto the flat face. A blunt tip does two things: it cannot drill, so the pilot hole stays the size the drawing specifies, and it stops the screw from running through thin sheet and breaking out on the far side.
The thread is a coarse single-lead form rolled up to the bearing ring. The pitch and the major diameter have to match the pilot hole the drawing specifies, because a cutting screw does not have the tolerance for a wrong hole that a self-drilling point has: it either cuts a thread that is too shallow or tears the wall. Metal cutting screws are therefore quoted against a hole size, not only against a thread.
Nickel plating follows the notching and the thread. Because a cutting screw’s notches are edges, plating over them rounds them slightly, and a heavy deposit makes the screw noticeably harder to start. The first article is driven into the sample material after plating, not before.
The family is quoted from M1 up, per drawing, with the recorded part in carbon steel and nickel. Custom lengths up to 2,000 mm are subject to DFM review after drawing submission; metal cutting screws run short in practice, because the thread is cutting into a hole in a thin or medium section rather than clamping a deep stack.
| Item | How it is defined | What we control |
|---|---|---|
| Thread | Coarse single-lead thread, rolled | Gauged per batch |
| Notches | Two or more flutes cut into the tip | Count, depth and edge condition on the first article |
| Tip | Blunt, flat, with the notches opening onto it | Checked on the projector |
| Pilot hole | Set by the thread and the material | Confirmed against a sample of the customer’s sheet |
| Head | Pan head with a Phillips recess | Diameter and height checked |
| Length | From under the head to the flat tip | Measured on the shop plate |
The pilot hole is the dimension the customer has to get right, and it is the one a drawing most often leaves out. A hole that is too small makes the screw hard to drive and strips the thread it just cut; one that is too large leaves a thread with too little material engaged, and it pulls out under load. The hole size belongs on the drawing next to the thread.
The notches have a second role: they give the chips somewhere to go. A cutting screw removes material, and in a blind hole that material has to exit along the flutes. Where the hole is deep and blind, the notch depth and the length of the threaded section are chosen so the chips can clear rather than pack under the head. That is the detail that separates metal cutting screws from a screw that only looks like one.
The choice between a cutting screw and a forming screw is the first decision in sheet metal, and it changes the hole, the tool and the finish of the joint.
| Type | What it does to the hole | Where it is used | What to watch |
|---|---|---|---|
| Thread cutting | Cuts a chip out of the wall | Sheet metal, plastics, hard materials | Chips must clear; hole size is critical |
| Thread forming | Displaces material into the thread | Light sheet, plastics, die castings | Needs a slightly different hole size |
| Self drilling | Drills and taps in one action | Sheet where the hole is not pre-drilled | Point wanders; swarf stays in the joint |
| Self tapping (gimlet) | Starts in wood and board | Timber, board, soft plastics | Not for metal without a drilled hole |
A cutting screw leaves a thread that is fully formed in the wall, with the chip taken out. That is the right answer in metal that is hard enough to resist being formed, and in plastics where displacing material builds stress and can crack the boss. Metal cutting screws are the safer choice wherever the material is brittle. The cost is chips: they have to clear, and in a sealed joint they do not.
A forming screw pushes material aside and leaves no chips, which is why it is preferred in electronics and in any assembly where loose metal is a risk. Its thread is formed by compression, so the material has to be soft enough to move without cracking, and the hole size is different from a cutting screw of the same thread.
The blunt tip is what keeps the joint honest. A pointed screw on thin sheet can start a hole of its own, wander off the pilot and break out; a flat tip on metal cutting screws cannot, so the screw goes where the hole is. That is also why these are the screws used where the panel is a visible face and a breakout would ruin it.
The recorded finish is nickel plating on carbon steel. Nickel is hard, bright and decorative, and it suits a visible pan head on a panel where a dull zinc screw would stand out.
| Finish | How it protects | Effect on the notches | Typical use |
|---|---|---|---|
| Nickel | Hard metallic deposit, bright | Edges rounded slightly; re-driven on test | Visible panels and instruments |
| White zinc | Sacrificial zinc, blue-white passivation | Thin; notches stay sharp | General indoor assembly |
| Zinc nickel | Alloy layer, higher corrosion resistance | Thicker; notches re-checked | Wet or industrial service |
| Black oxide | Thin conversion film, oiled | Almost no change | Dark assemblies |
| Stainless (equivalent part) | Alloy provides protection | No coating | Wash-down and coastal use |
Plating and a cutting edge are in tension. A deposit that is good for corrosion resistance rounds the notch and makes the screw harder to start, and a deposit that is thin enough to leave a sharp edge protects less. On metal cutting screws the finish is therefore agreed with the hardness of the material being cut, and the first article is driven after plating. Every batch of metal cutting screws is checked in that condition, because the edge is what does the work.
Where the joint is wet, a nickel finish is the wrong answer even though it looks right: nickel over steel is a hard coating that can crack and let the steel corrode underneath. A zinc-nickel or a stainless version is the honest specification for anything outdoors or washed.
Three applications where cutting a thread is better than forming one:
| Where it sits | The screw cuts its own thread into a pilot hole in sheet, clamping a bracket, a cover or a component to the panel. |
| When it goes wrong | A pointed screw wanders off the pilot and breaks out of a thin panel, and a hole that is too small strips the thread as it is cut. |
| Why it happens | The sheet is thin, the face is visible, and the hole is pre-drilled on a punch or a laser. |
| What we control | Notch condition and tip checked on the first article, and the pilot hole confirmed against a sample of the sheet. |
| Where it sits | The screw cuts a thread into a moulded boss or a plate, where forming the material would build stress and crack it. |
| When it goes wrong | A forming screw splits a thin boss, and a cutting screw with a blunt tip driven into too small a hole tears the wall. |
| Why it happens | The material is brittle or reinforced, the boss is thin, and the joint is made once. |
| What we control | Pilot hole, notch and thread checked against a sample of the actual moulding. |
| Where it sits | The screw fixes a panel, a guard or a corner bracket to a painted or coated steel skin, driven from the outside. |
| When it goes wrong | A pointed screw that breaks out chips the coating on the far side, and a head that is too small dishes the skin. |
| Why it happens | The panel is visible, the coating has to stay intact, and the fixing is on a production line. |
| What we control | Tip and notches checked, head diameter verified, and the first article driven into a coated sample. |
Four reasons that matter on a thread-cutting screw, each tied to what the drawing has to prove:
|
Pilot hole and notch reviewed together
The thread, the notch form and the pilot hole are reviewed together against the material, so a screw that will not cut is raised before tooling. Basis: Notch and pilot hole reviewed as one set. |
Thread rolled, notches cut last
The thread is rolled up to the head and the notches are cut afterwards, so the cutting edges are formed rather than closed up by the roll. Basis: Notches cut after rolling. |
|
Notch and tip checked on the part
The notches are checked for depth and edge condition, the tip for flatness, and the first article is driven into a sample of the sheet. Basis: First article driven into the sheet sample. |
First article to repeat production
The first article fixes the drawing revision, wire heat, die set, thread roll and notch cutter; repeat orders are compared against that record. Basis: First article signed off before the batch is released. |
Shi Shi Tong forms these metal cutting screws on a single-die header that upsets the pan head and the Phillips recess in one stroke, rolls the coarse thread up to the head, cuts the notches into the tip and leaves a blunt flat end. The parts are nickel plated after notching. The first part of every run is measured on the head and the tip, and driven into a sample of the customer’s sheet, before the batch continues.
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The notch cutter is the tool that has to be right. A worn cutter leaves a notch that is shallow and burred, and a burred edge does not cut so much as rub: the screw drives hard, heats the hole and strips the thread it has just made. That is why the notches are checked on every first article rather than sampled from a drawing.
What decides whether metal cutting screws pass is the notches, the tip, the thread, the head and the finish. The inspection agreement covers those, and the criteria come from the drawing.
Notches and tip on the projector |
Thread gauged per batch |
Hardness testing against the property class |
Salt-spray testing of the nickel plate |
The notches are checked on the magnified first article for depth, edge condition and whether they open cleanly onto the flat tip. A notch that is present but does not reach the tip does not start the cut, and the screw then behaves like a blunt self-tapping screw with no cutting action at all.
The driving test is the real acceptance. The first article is driven into the specified pilot hole in a sample of the customer’s material at the production torque, then removed to look at the thread it cut. A clean thread with a chip that has cleared is a pass; a torn or shallow thread points at the hole size or the notch, and both are the shop’s problem to settle before the batch runs.
Every shipment of metal cutting screws is traceable to the wire it was made from. 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 cutting screw the first article is driven into a sample of the customer’s sheet, because the notch and the pilot hole only prove themselves together. Buyers visit during the process to review samples and to see how the tips are notched.
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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 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 |
A thread-cutting screw with notches cut into the tip, so it cuts its own thread in a pilot hole in sheet, plastic or a similar material.
A cutting screw removes a chip; a forming or tapping screw displaces material. The hole sizes differ, and a cutting screw needs somewhere for the chip to go.
So the screw cannot drill its own hole or break out through a thin panel. It goes only where a pilot hole has been made.
It depends on the thread and the material, and it belongs on the drawing. Too small and the thread strips as it is cut; too large and there is too little thread engaged.
It rounds it slightly, which is why the first article is driven after plating. A heavy deposit makes a cutting screw noticeably harder to start.
Thread size and pitch, head diameter and height, recess, notch form, tip, length and datum, pilot hole, material and finish.
How a metal cutting screw project runs from drawing to repeat delivery:
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1
Send the drawing and a material sample
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→ |
2
Pilot hole and notch review
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→ |
3
First article driven into the sheet
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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 thread size and pitch, head diameter and height, recess, notch form, tip, length and datum, the pilot hole and the material being joined.
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Thread and pitch
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Head and recess
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Notch form
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Tip
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Length and datum
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Pilot hole
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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
