---
title: "Flow-Drilling Screws"
description: "Flow-Drilling Screws to Trade series (flow-drilling screws): sizes M3 to M6. 5 catalogued sizes with materials and finishes."
url: https://engineeringhardware.com/fastener/flow-drilling-screws/
source: Engineering Hardware & Fasteners
---

# Flow-Drilling Screws

Screws · Flow-Drilling Screws

5 catalogued sizes, dimensioned to Trade series (flow-drilling screws). Pick any row and the technical drawing redraws to it.

Flow-Drilling Screws to Trade series (flow-drilling screws) are catalogued in sizes M3 to M6. 5 sizes are held in the table below, and the technical drawing redraws to whichever row you select.

- **Standard:** Trade series (flow-drilling screws)
- **Size range:** M3-M6
- **Catalogued sizes:** 5

Dimensions are nominal values from the governing standard. Confirm the tolerance class for your application before ordering.

![Flow-Drilling Screws technical product image](https://engineeringhardware.com/wp-content/uploads/2026/09/Flow-Drilling-Screws.webp)

Product catalog

## Related Flow-Drilling Screws products

[![Premium Hex Self-Drilling Screws for Wood Roofing Projects](https://img.engineeringhardware.com/Premium-Hex-Self-Drilling-Screws-for-Wood-Roofing-Projects.webp)](https://engineeringhardware.com/product/premium-hex-self-drilling-screws-for-wood-roofing-projects/)

Self-Drilling & Tek Screws

### [Premium Hex Self-Drilling Screws for Wood Roofing Projects](https://engineeringhardware.com/product/premium-hex-self-drilling-screws-for-wood-roofing-projects/)

DIN · Stainless Steel

**US$0.012 – 0.06**MOQ 1,000 pieces

[![Zinc-Plated Fine Thread Self-Drilling Drywall Screw](https://img.engineeringhardware.com/Zinc-Plated-Fine-Thread-Self-Drilling-Drywall-Screw.webp)](https://engineeringhardware.com/product/zinc-plated-fine-thread-self-drilling-drywall-screw/)

Self-Drilling & Tek Screws

### [Zinc-Plated Fine Thread Self-Drilling Drywall Screw](https://engineeringhardware.com/product/zinc-plated-fine-thread-self-drilling-drywall-screw/)

Bugle Head · DIN

**US$1.56 – 1.80**MOQ 1 mpcs

[![Cement Board Use Non-Slip Countersunk Head Csk Self Drilling Screws with Ears or Wing](https://img.engineeringhardware.com/Cement-Board-Use-Non-Slip-Countersunk-Head-Csk-Self-Drilling-Screws-with-Ears-or-Wing.webp)](https://engineeringhardware.com/product/cement-board-use-non-slip-countersunk-head-csk-self-drilling-screws-with-ears-or-wing/)

Self-Drilling & Tek Screws

### [Cement Board Use Non-Slip Countersunk Head Csk Self Drilling Screws with Ears or Wing](https://engineeringhardware.com/product/cement-board-use-non-slip-countersunk-head-csk-self-drilling-screws-with-ears-or-wing/)

Self Drilling · DIN, GB, GOST

**US$1,236 – 1,296**MOQ 1 ton

[![Dacromet Coated Hex Washer Head Self-Drilling Screw with EPDM Washer](https://img.engineeringhardware.com/Dacromet-Coated-Hex-Washer-Head-Self-Drilling-Screw-with-EPDM-Washer.webp)](https://engineeringhardware.com/product/dacromet-coated-hex-washer-head-self-drilling-screw-with-epdm-washer/)

Self-Drilling & Tek Screws

### [Dacromet Coated Hex Washer Head Self-Drilling Screw with EPDM Washer](https://engineeringhardware.com/product/dacromet-coated-hex-washer-head-self-drilling-screw-with-epdm-washer/)

Nom · Galvanized

**US$0.036 – 0.12**MOQ 50,000 pieces

[![Chipboard Screw/Self Drilling Screw/Roofing Screw/Wood Screw/Drywall Screw/Anti-Split Fast Drive Trox Screws](https://img.engineeringhardware.com/Chipboard-Screw-Self-Drilling-Screw-Roofing-Screw-Wood-Screw-Drywall-Screw-Anti-Split-Fast-Drive-Trox-Screws.webp)](https://engineeringhardware.com/product/chipboard-screw-self-drilling-screw-roofing-screw-wood-screw-drywall-screw-anti/)

Self-Drilling & Tek Screws

### [Chipboard Screw/Self Drilling Screw/Roofing Screw/Wood Screw/Drywall Screw/Anti-Split Fast Drive Trox Screws](https://engineeringhardware.com/product/chipboard-screw-self-drilling-screw-roofing-screw-wood-screw-drywall-screw-anti/)

Countersunk Head · DIN, GB, ANSI, BSW, JIS

**Price on request**MOQ 1 ton

[![Made in China DIN7504K Roofing Screw, Hex Washer Head Self Drilling Screw, Tek Screw with EPDM Washer / Rubber Washer](https://img.engineeringhardware.com/Made-in-China-DIN7504K-Roofing-Screw-Hex-Washer-Head-Self-Drilling-Screw-Tek-Screw-with-EPDM-Washer-Rubber-Washer.webp)](https://engineeringhardware.com/product/made-in-china-din7504k-roofing-screw-hex-washer-head-self-drilling-screw-tek-screw/)

Self-Drilling & Tek Screws

### [Made in China DIN7504K Roofing Screw, Hex Washer Head Self Drilling Screw, Tek Screw with EPDM Washer / Rubber Washer](https://engineeringhardware.com/product/made-in-china-din7504k-roofing-screw-hex-washer-head-self-drilling-screw-tek-screw/)

Hexagon Head · DIN, GB, ANSI, BSW, DIN7504K/DIN7504p/DIN7505A/DIN7981/…

**US$0.12 – 1.20**MOQ 1,000 pieces

[View all Self-Drilling & Tek Screws →](https://engineeringhardware.com/fastener-products/screws/self-drilling-tek-screws/) [Full product catalog](https://engineeringhardware.com/products/)

## Materials & Grades

Select a material class to see the grades we supply it in. Each designation is listed with its ISO/EN, AISI/SAE, JIS and GB equivalents.

Stainless Steel38 Carbon Steel66 Alloy Steel41 Bearing Steel5 Spring Steel25 Aluminum and Aluminum Alloys21 Brass17 Bronze11 Copper8 Titanium and Titanium Alloys18 Nickel and Nickel Alloys22 Iron-Nickel and High-Temperature Alloys10 Tool Steel and Specialty Hardened Steel9 Structural and Construction Steel9

### Stainless Steel

#### Austenitic Stainless Steel

- A1 AISI 303 · SAE 303 · SUS303 · EN 1.4305 · X8CrNiS18-9
- A2 AISI 304 · SAE 304 · SUS304 · EN 1.4301 · X5CrNi18-10 · 06Cr19Ni10
- 304L AISI 304L · SUS304L · EN 1.4307 · X2CrNi18-9 · 022Cr19Ni10
- 302 AISI 302 · SUS302 · EN 1.4310
- 305 AISI 305 · SUS305 · EN 1.4303
- A4 AISI 316 · SAE 316 · SUS316 · EN 1.4401 · X5CrNiMo17-12-2 · 06Cr17Ni12Mo2
- 316L AISI 316L · SUS316L · EN 1.4404 · X2CrNiMo17-12-2 · 022Cr17Ni12Mo2
- 321 AISI 321 · SUS321 · EN 1.4541 · X6CrNiTi18-10
- 310 / 310S AISI 310 · AISI 310S · SUS310S · EN 1.4845
- 302HQ AISI 302HQ
- A3
- A5
- 347 AISI 347 · SUS347 · EN 1.4550 · X6CrNiNb18-10
- 309 / 309S AISI 309 · AISI 309S · SUS309S

#### Martensitic Stainless Steel

- AISI 410 SUS410 · EN 1.4006 · X12Cr13 · 12Cr13
- AISI 420 SUS420J1 · SUS420J2 · EN 1.4021 · EN 1.4028 · 20Cr13 · 30Cr13
- AISI 431 SUS431 · EN 1.4057 · X17CrNi16-2
- C1
- C3
- C4
- AISI 440A
- AISI 440B
- AISI 440C SUS440C · EN 1.4125

#### Ferritic Stainless Steel

- AISI 430 SUS430 · EN 1.4016 · X6Cr17 · 10Cr17
- F1
- AISI 434
- AISI 444

#### Precipitation-Hardening Stainless Steel

- 17-4 PH AISI 630 · UNS S17400 · SUS630 · EN 1.4542 · X5CrNiCuNb16-4
- 15-5 PH UNS S15500
- 17-7 PH UNS S17700

#### Duplex and Super Duplex Stainless Steel

- Duplex 2205 UNS S31803 · UNS S32205 · EN 1.4462
- Super Duplex 2507 UNS S32750 · EN 1.4410
- D2
- D4
- D6
- D8
- Lean Duplex 2101 UNS S32101
- Super Duplex S32760 UNS S32760 · EN 1.4501

### Carbon Steel

#### Low-Carbon Steel

- SAE 1006
- SAE 1008
- SAE 1010
- SAE 1018
- SAE 1020
- Q195
- Q235
- SAE 1012
- SAE 1015
- Q215
- ML08
- ML08Al
- ML10
- ML15
- ML20
- SWRCH6A
- SWRCH8A
- SWRCH10A
- SWRCH12A
- SWRCH15A
- SWRCH18A

#### Medium-Carbon Steel

- SAE 1035
- SAE 1045
- S45C
- C45
- SAE 1030
- SAE 1040
- SAE 1050
- 30
- 35
- 40
- 45
- 50
- S35C
- S40C
- S50C
- C35
- C40

#### High-Carbon Steel

- SAE 1060
- SAE 1070
- 65Mn
- SAE 1065
- SAE 1075
- SAE 1080
- SAE 1085
- SAE 1090
- SAE 1095
- 60
- 65
- 70
- 75
- 80
- 85

#### Cold-Heading Steel

- SWRCH22A
- 10B21
- SWRCH22K
- SWRCH25K
- SWRCH30K
- SWRCH35K
- SWRCH40K
- ML20Mn
- ML25
- ML30
- ML35
- ML40
- 15B25

### Alloy Steel

#### Chromium Steel

- 40Cr
- 45Cr
- AISI 5140
- SAE 5140
- AISI 5120
- SAE 5120
- SCr420
- SCr440

#### Chromium-Molybdenum Steel

- 35CrMo
- 42CrMo
- AISI 4140
- SCM435
- SCM440
- 42CrMo4
- 30CrMo
- AISI 4130
- SAE 4130
- SAE 4140
- AISI 4142
- AISI 4145
- SCM415
- SCM420
- SCM445
- EN 1.7220
- EN 1.7225
- 25CrMo4
- 34CrMo4

#### Nickel-Chromium-Molybdenum Steel

- AISI 4340
- SAE 4340
- 40CrNiMo
- SNCM439
- EN 1.6511
- 36CrNiMo4

#### Boron Alloy Steel

- 10B22
- 10B21
- 15B21
- 15B25
- 20MnTiB
- 20Mn2B
- 35VB
- 40MnB

### Bearing Steel

#### Bearing Steel

- GCr15
- AISI 52100 SAE 52100 · UNS G52986
- SUJ2
- 100Cr6 EN 1.3505
- GCr15SiMn

### Spring Steel

#### Carbon Spring Steel

- SAE 1065
- SAE 1070
- SAE 1075
- SAE 1080
- SAE 1095
- 65
- 70
- 75
- 80
- 65Mn

#### Silicon-Manganese Spring Steel

- 60Si2Mn
- 60Si2MnA
- SUP6
- SUP7

#### Chromium-Vanadium Spring Steel

- 50CrVA
- SAE 6150
- AISI 6150
- SUP10

#### Stainless Spring Steel

- AISI 301
- SUS301
- EN 1.4310
- AISI 302
- AISI 304
- AISI 316
- 17-7 PH

### Aluminum and Aluminum Alloys

#### Commercially Pure Aluminum

- 1050
- 1060
- 1070
- 1100

#### 2xxx Series Aluminum

- 2024
- 2011
- 2014
- 2017

#### 5xxx Series Aluminum

- 5052
- 5083
- 5754

#### 6xxx Series Aluminum

- 6061
- 6061-T6
- 6063
- 6082
- 6082-T6

#### 7xxx Series Aluminum

- 7075
- 7075-T6
- 7005
- 7050
- 7075-T73

### Brass

#### Free-Cutting Brass

- C36000
- H62
- HPb59-1
- C3601
- C3602
- C3604
- CuZn36Pb3
- CuZn39Pb3
- EN CW614N
- EN CW617N
- H65

#### Lead-Free Brass

- C69300
- C27450
- CW510L
- CW511L

#### Naval Brass

- C46400
- CuZn39Sn1

### Bronze

#### Silicon Bronze

- C65500
- C65100
- C65600

#### Phosphor Bronze

- C51000
- C52100
- CuSn6
- CuSn8

#### Aluminum Bronze

- C95400
- C95500
- C63000
- CuAl10Ni5Fe4

### Copper

#### Copper

- C11000
- T2
- C10100
- C10200
- C12200
- T1
- TU1
- TU2

### Titanium and Titanium Alloys

#### Commercially Pure Titanium

- Grade 2
- Grade 1
- Grade 3
- Grade 4
- TA1
- TA2
- TA3

#### Alpha-Beta Titanium Alloys

- Grade 5
- Ti-6Al-4V
- TC4
- UNS R56400

#### Low-Interstitial Grade

- Grade 23
- Ti-6Al-4V ELI
- UNS R56407

#### Other Titanium Fastener Alloys

- Ti-6Al-6V-2Sn
- Ti-6Al-2Sn-4Zr-2Mo
- Beta-C titanium
- Ti-10V-2Fe-3Al

### Nickel and Nickel Alloys

#### Commercially Pure Nickel

- Nickel 200
- UNS N02200
- Nickel 201
- UNS N02201

#### Inconel Alloys

- Inconel 625 UNS N06625
- Inconel 718 UNS N07718
- Inconel 600 UNS N06600
- Inconel 601 UNS N06601
- Inconel 686 UNS N06686
- Inconel X-750 UNS N07750

#### Monel Alloys

- Monel 400 UNS N04400
- Monel K-500 UNS N05500

#### Hastelloy Alloys

- Hastelloy C-276 UNS N10276
- Hastelloy C-22 UNS N06022
- Hastelloy B-2 UNS N10665
- Hastelloy B-3 UNS N10675
- Hastelloy X UNS N06002

#### Other Nickel Alloys

- Alloy 20 UNS N08020
- Alloy 625
- Alloy 718
- Alloy 825 UNS N08825
- Alloy 925 UNS N09925

### Iron-Nickel and High-Temperature Alloys

#### A286

- A-286
- UNS S66286
- EN 1.4980

#### Invar

- Invar 36
- Alloy 36
- UNS K93600
- FeNi36

#### Alloy 42

- Alloy 42
- UNS K94100
- FeNi42

### Tool Steel and Specialty Hardened Steel

#### Tool Steel and Specialty Hardened Steel

- AISI D2
- AISI H13
- SKD11
- Cr12MoV
- AISI O1
- AISI A2
- AISI S7
- SKD61
- 9CrSi

### Structural and Construction Steel

#### Structural and Construction Steel

- ASTM A36
- Q235B
- Q355B
- S355JR
- Q235C
- Q355C
- S235JR
- S275JR
- S355J2

## Applications & Industries

What Flow-Drilling Screws are specified for, industry by industry. Stocked from M3 to M6.

### Industries that specify Flow-Drilling Screws

- **Magnesium housings:** One-side fastening avoids a loose nut inside a closed section.
- **Industrial panels:** The clearance and sheet ranges define the process window.
- **Automotive body structures:** Flow-drilling screws create a threaded boss through one-side sheet access.
- **Aluminum fabrication:** The process joins aluminum sheet without a separate pre-drilled thread.
- **Machine building & OEM:** The default fastener on production equipment: covers, brackets, motor mounts and sub-assemblies tightened to a specified torque.
- **Automotive & transport:** Chassis, driveline and body fixings that see vibration and are assembled to a controlled preload.

### Typical applications

- selecting the process for the sheet thickness
- using the specified drive and head for the assembly tool
- flow-drilling a thread into steel, aluminum or magnesium
- matching the clearance-hole range to the screw size
- assemblies that are dismantled for service and re-torqued
- joints where the property class is stated on the drawing

### Service conditions to specify against

- **Marine and coastal:** Available in A4 (316) stainless for chloride exposure — coastal structures, pool halls, water treatment and deck hardware, where A2 will eventually pit.
- **High load:** Supplied in ISO 898-1 property classes, so the joint can be designed to a stated proof load and tightened to a calculated torque rather than by feel.
- **Torque and preload:** The joint is designed around bolt tension, so lubrication, coating and the friction coefficient all change the torque figure — state them together.

### Where to use something else

- Do not use a flow-drilling screw outside its material or sheet-thickness window; heat and thread formation are process-dependent.
- Do not use a machine thread into unthreaded sheet or timber; use a tapping screw, rivet nut or insert made for that parent material.

[Full application guide: where Flow-Drilling Screws are used, how to specify them, and the cases they are wrong for](https://engineeringhardware.com/applications/flow-drilling-screws/)

## Technical Drawing

Dimensioned line drawing of M3 Flow-Drilling Screws to Trade series (flow-drilling screws). Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.

- **Clearance-hole diameter (mm):** 3.6~4.0
- **Steel sheet range (mm):** 0.3~1.8
- **Aluminum sheet range (mm):** 0.8~5.0
- **Magnesium sheet range (mm):** 0.8~3.5
- **Example drive / head:** varies by series

## Dimensions & Specifications (Trade series (flow-drilling screws))

Every row below is a starting point for the customizer above — pick any size and the drawing will redraw to that row.

| Thread size | Clearance-hole diameter (mm) | Steel sheet range (mm) | Aluminum sheet range (mm) | Magnesium sheet range (mm) | Example drive / head |
| --- | --- | --- | --- | --- | --- |
| [M3](https://engineeringhardware.com/guide/size/m3-flow-drilling-screws/) | 3.6~4.0 | 0.3~1.8 | 0.8~5.0 | 0.8~3.5 | varies by series |
| [M3.5](https://engineeringhardware.com/guide/size/m3-5-flow-drilling-screws/) | 4.3~4.8 | 0.3~1.8 | 0.8~5.0 | 0.8~3.5 | varies by series |
| [M4](https://engineeringhardware.com/guide/size/m4-flow-drilling-screws/) | 5.1~5.7 | 0.3~1.8 | 0.8~5.0 | 0.8~3.5 | M4×20 stainless; PH2/PZ2/T25 examples |
| [M5](https://engineeringhardware.com/guide/size/m5-flow-drilling-screws/) | 6.7~7.4 | 0.3~1.8 | 0.8~5.0 | 0.8~3.5 | M5×20 stainless; PH2/PZ2/T25 examples |
| [M6](https://engineeringhardware.com/guide/size/m6-flow-drilling-screws/) | 8.2~9.1 | 0.3~1.8 | 0.8~5.0 | 0.8~3.5 | varies by series |

Flow-Drilling Screws conform to Trade series (flow-drilling screws). As screws, they are specified by the dimensions in the table below; this page also covers materials, finishes and typical uses.

## What Are Flow-Drilling Screws?

Flow-Drilling Screws are screws defined by Trade series (flow-drilling screws). They are selected by thread size and the dimensional characteristics shown below, and are available in a range of materials and finishes to suit the application and environment.

## Materials & Finishes

Common materials include carbon steel (typically zinc plated or hot-dip galvanized), alloy steel in property classes 8.8, 10.9 and 12.9, and stainless steel A2 (304) or A4 (316) for corrosion resistance. Specify the material, property class and surface finish appropriate to your load and environment.

## Specification Guides

Each size, material and standard of Flow-Drilling Screws has its own reference page with the figures for that one configuration.

## Goes With

Hardware commonly specified alongside Flow-Drilling Screws.

## Pricing

Flow-Drilling Screws are supplied to order. Pricing starts from approximately US$0.080 per piece for standard sizes in carbon steel; final pricing depends on size, material, finish and order quantity (MOQ applies). Submit your exact configuration with the quote form above.

Custom manufacturing · Made to drawing

## Need a flow-drilling screws outside the standard range?

Material and finish are usually what drives a special — a grade the standard part is not stocked in, or a coating chosen against a salt-spray figure instead of a default. Made by cold heading or warm forging.

Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

[Custom screw manufacturing](https://engineeringhardware.com/custom/screws/)[Send a drawing](https://engineeringhardware.com/custom/screws/#rfq)

Inside the plant

## Manufactured in our own plant

This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided.

1. ![Wire rod feeding into a cold heading machine](https://engineeringhardware.com/wp-content/uploads/2026/08/09-wire-rod-feed-cold-heading-machine.webp) 01 **Cold heading** Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail. Head dimensions and under-head radius checked at set-up and per shift.
2. ![Thread rolling machine producing bolt threads](https://engineeringhardware.com/wp-content/uploads/2026/08/03-thread-rolling-machine-bolt-production.webp) 02 **Thread rolling** Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch. Go / no-go ring gauges to ISO 965 tolerance class 6g.
3. ![Baskets of bolts staged for heat treatment](https://engineeringhardware.com/wp-content/uploads/2026/08/05-heat-treatment-baskets-black-bolts.webp) 03 **Heat treatment** Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it. Core hardness and tensile tested per lot to ISO 898-1.
4. ![Zinc plated bolts in a treatment basket](https://engineeringhardware.com/wp-content/uploads/2026/08/23-zinc-plated-bolts-treatment-basket.webp) 04 **Surface treatment** Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list. Coating thickness and neutral salt spray hours to ISO 9227.

## Frequently Asked Questions

### Which standard governs Flow-Drilling Screws?

Flow-Drilling Screws are manufactured to Trade series (flow-drilling screws). The dimensional values on this page follow that standard.

### Which sizes of Flow-Drilling Screws does Engineering Hardware supply?

The table on this page lists 5 sizes for Flow-Drilling Screws, ranging from M3 to M6. Sizes outside the table can be quoted on request.

### In which materials are Flow-Drilling Screws supplied?

Flow-Drilling Screws are supplied in alloy steel (typically 10.9 / 12.9 for socket screws), carbon steel and stainless A2 / A4, with finishes including zinc plating, hot-dip galvanizing and black oxide. Choose material and finish to suit the load and the service environment for Flow-Drilling Screws.

### How do I request a quotation?

Use the parametric drawing on this page to set the exact configuration (size, material, finish) and click "Request this configuration" — a specialist from Engineering Hardware will respond within one business day.