What is a countersunk screw?The Ultimate Guide

What is a countersinking screw? Countersunk head screw is also known as a flat head screw. It has a smooth head and a tapered bottom, allowing it to blend naturally into the surface of the object it secures. Without looking carefully, it can be difficult to spot. Now, let’s discuss its types, standards, and uses in detail.

Types of countersunk screw    

Categorize by Thread

Types of countersunk screw1


There are many varieties of countersunk head screws(flat head screw), and they are divided into two types according to the shape of the tail. One is countersunk head pointed tail screws, which all have pointed self-tapping threads. For example, wood screws, self-tapping screws, deck screws, Drywall screws are all pointed countersunk head screws.


Types of countersunk screw2

The other is countersunk head flat tail screws, also known as machine screws, which are usually made with fine threads.

Categorize by Driver Type

Categorize by Driver Type

There are also many driving methods for countersunk(flat) head screws, such as Philips slotted, flat slotted, trox slotted, pentagonal slotted, inner hexagonal slotted, triangular slotted, etc. These screws can also be made into self-tapping threads or machine threads.

Standard for countersunk screws    

Machine screw type standard

The international standards for countersunk head machine screws include: DIN799/ISO10642/JISB1194 hex socket screws,DIN965/ISO7046 flat head cross slotted screws, DIN963/DIN964/ISO2009/JISB1101F flat slotted machine screws, ISO14581/trox counter sunk head machine screws, etc.

Standard for tapping thread flat head screw

ISO7050/JISB1122F cross self-tapping screw, DIN7962/ISO1482 flat slotted self-tapping screw, ISO14586 Hexalobular socket countersunk head tapping screws, DIN7505 Chipboard Screw, DIN7504P cross Self drilling, etc.

Countersunk screw dimensions    

The common sizes of countersunk head screws range from M2 to M30, M2, M3, M4, M5, M6, M8, M10, M12, M14, M16, M20, M22, M24, etc. The length ranges from 10mm to 100mm. Of course, if you want to buy larger specifications, you can contact us to customize.

What is the angle of a countersunk screw

angle of a countersunk screw

The conventional screw countersink angle is 90 degrees 110 120 degrees, but the countersunk head screw angle for aviation is 100 and 130 degrees. You can also customize the screw angle according to your needs.

What is a Counter sunk screw use for?


Countersunk head screws can be divided into the following categories according to application scenarios

  1. Furniture industry, such as sofas, beds, tables and benches are all assembled with this kind of screw. The countersunk head can be embedded in wood, and there will be no protruding parts that will affect the beauty.
  2. In the construction industry, stairs, doors and windows, railings and many other places are fixed with countersunk head screws.
  3. Appliance industry, it can be used to fix the shell and internal parts of TV, air conditioner, refrigerator and other household appliances.
  4. Machinery industry, assembly of some precision machinery such as CNC lathes, connection and fixation of parts.
  5. In the automobile industry, countersunk head screws are also used from automobile body to engine group, including internal electronic components.
  6. Corrosion-resistant countersunk head screws such as titanium alloy or stainless steel are used in aviation industry, wings and fuselages, landing gear, engine parts, and interior of passenger aircraft.

What are the advantages of countersinking screws?  

Countersunk head screws have many advantages such as beautiful and diverse shape, low cost, simple installation method, space saving, good fastening effect, low maintenance cost, easy disassembly, and wide range of adaptability.

Installation and disassembly of countersunk screws

Before installation, the position of the screw should be marked first, and the hole should be reamed with an electric drill according to its head angle. The hole should be slightly larger than the conical head of the screw. After reaming, choose a screwdriver or tool corresponding to the groove type to tighten it.

The disassembly method is also very simple. Unscrew it in the opposite direction with a screwdriver. The rusty screw can be soaked with some lubricating oil for a while before unscrewing it. When the screw is broken or difficult to take out, a special tool must be used to remove it.


The above is the introduction to countersunk head screws. If you have other questions, please contact us online. We provide one-stop fastener shopping, supply a variety of standard bolts, screws, nuts, washers, threaded rods. Customized special fasteners, stamping parts are also available

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