Taiwan Leading Hand-Tool Maker

How to design and make the good sales bit sockets? (detail chart)

  • 2020-03-11

"I Don't care who make what, I Just Like MY TOOLS TO NOT FAIL"

This expresses how most mechanics and technicians feel. They hope their hand tools will never fall apart. Unfortunately, some parts will eventually break or get worn out.

What are bit sockets? What causes them to break or to wear out? How do you select the right bit sockets?

A bit socket is composed of a bit and a socket. The bit is the external part, which comes in a standard shape, such as hex, Torx or slot. The socket is the bottom part, which has a square drive hole. You can drive a socket with a drive tool, such as a ratchet handle, impact wrench or power wrench.

Because a bit socket can be driven by square drive hole, the torque transmission is more stable and efficient than when using only a bit. A bit socket is a better choice for larger bolts and nuts with high torque requirements, such as those used in vehicles or large machines.

bit socket Tien-I 

(Comparison photos for bit sockets and bits)

The tip of a bit socket is easily worn down, deformed or broken during torque transmission, as this is when the tip of a bit is the most vulnerable. That’s because the torque is concentrated on a few specific points. When the same force is applied, a Phillips bit or a slotted bit will be more likely to deform or break than a hex bit or a Torx bit, because the torque is focused on few points rather than being evenly distributed across the entire connection line.

For a detailed explanation with diagrams, please check below link: 
“What Caused Stripped Screw?”

These are four types of bit sockets: manual two-piece bit sockets; manual one-piece bit sockets; replaceable bit sockets; and one-piece impact bit sockets. To learn more about each type, please check out the pages linked below.

Manual Two Piece Bit Socket ⼿動起⼦套筒 (兩體式)
Manual Bit Socket (One Piece) ⼿動起⼦套筒 (⼀體式)
Replaceable Bit socket 換式起⼦套筒 (兩體式)
Impact Bit socket (One Piece) 氣動起⼦套筒 (⼀體式) 

bit socket comparing sheet  

The photos above depict the four types of bit sockets. Let’s discuss each type of bit socket in a bit more detail, including specifications and materials.

Manual Two Piece Bit Socket 

A manual two-piece bit socket comprises two pieces: the socket and the bit. The socket is made of chrome vanadium steel. Tien-I, as Taiwan leading manufacturer, uses Taiwan-made alloy steel, CR-V 50BV30, with high-tech cold forged and heat treatment to ensure consistent quality as well as hardness and torque stable performance in mass production.

To learn more about the benefits of CR-V, please click on the link below.

Tien-I Chooses Taiwanese Chrome Vanadium Steel for Durability and Resilience

The bit is made of S2, Si alloyed steel (Shock-resistant, S-type)

S2 is a widely used alloyed steel that is known to most mechanics and technicians. The hardness of S2 is around HRC 59-67, because it contains a high percentage of silicon. Considering that the hardness of a samurai sword is around HRC 60, a hardness of above HRC 59 is exceptional.

















However, S2 is not always the right choice for making bits. If a mechanic were to apply too much force, would you prefer the bit or the bolt to break?

In most circumstances, it would be preferable for the bit to break, because a broken bolt—or worse, a stripped case and damaged thread—will cost the mechanic more time. Time is money, especially when you’re dealing with a professional mechanic. That’s why some bolts should be worked on only manually and never with air or power tools. You should never use an impact wrench or a power wrench on a manual bit socket.

Manual Bit Socket (One Piece)

One-piece manual bit sockets are usually made of SNCM 8660, nickel chrome molybdenum steel; or S2, Si alloyed steel (shock-resistant, S- type). The hardness of SNCM 8660 is around HRC 55-59, lower than that of S2. However, the balance between bit durability and the possibility of stripping is a key point. When considering small sizes with higher return rates, such as Torx T20, Tien-I would work with its customers to choose the right material to optimize the return rate of specific sizes.

One-piece bit sockets don’t have a socket part, so they can be extremely short (below 20 – 30 mm). The ultra-short length makes them easy to use in confined spaces.


 super short bit

Replaceable Bit socket

The advantage of a replaceable bit socket is that the bit itself is replaceable. As the tip is the part most likely to break, replaceable bit sockets can help frequent users to save money. After all, it is cheaper and easier to replace the bit than it is to replace the entire bit socket. The design facilitates speedy replacement of the bit. As shown below, the socket and the bit are connected by a screw. Simply loosen the screw, replace the bit, tighten the screw, and you’re done.bit socket replaceable

Impact Bit socket (One Piece)

An impact bit socket is usually made of SNCM 8660, nickel chromium molybdenum steel; or CR-MO SCM440, chromium molybdenum steel.

To learn more about these materials, please click link below. "Impact Socket Material, Chrome Molybdenum Steel, CR-MO”

When considering torque application and bit durability, we should know each type of bit socket and how well it is suited to a specific work area or purpose.

If you occasionally repair your car at home, manual bit sockets can do a fantastic job. On the other hand, impact bit sockets and replaceable bit sockets would be a better choice for workshop mechanics or factory workers on an assembly line. Cost and time efficiency are both key factors to consider when choosing bit sockets.


How to choose the right bit sockets?

This depends primarily on which country or region you are in, because warranty coverage varies according to country. Brand warranty coverage is more significant than product quality. In USA, some tool brands will have a lifetime warranty. Even though bit sockets are supposed to be consumable items, some tool brands have extended the warranty coverage to include the bit, simply because the hand-tool market is so competitive. If the bit tip wears down or breaks while the item is still under warranty, the tool brand will send a new bit socket to replace it. While this service is great for end users, it is a nightmare for manufacturers.

As a leading Taiwanese manufacturer of bit sockets, Tien-I stands alongside its professional tool brands in facing this challenge, by analyzing the return rate and offering alternative solutions to drive down the return rate. Our engineers strive for continued improvement.

In the hand-tool market, competition is fierce. High-end brands vie to offer the highest quality as well as unmatched service and warranty coverage. On many online forums, you can find people debating about every aspect of hand tools, including prices, quality and service. Are bits made in Germany more durable than those made in the USA? These online discussions are of interest mainly to local distributors.

The chart below shows Tien-I’s complete range of bit sockets, categorized by size and length. It’s worth noting that with bit sockets, longer is not necessarily better, as the longer the bit socket, the more susceptible to breakage.

 Tien-I has been providing bit sockets for the hand-tool industry for more than thirty years. To request further information, including any questions you may have about size, torque performance and material, please contact our over 30 years experienced sales team.

Tien-I manufactures manual bit sockets and impact bit sockets to international ANSI and/or DIN & ISO standards. If you’re looking for a supplier of consistent quality bit sockets, please contact with Tien-I Sales team.

To find out more about the various types of bit sockets Tien-I provides, please check out the following pages linked below.

Two Pieces Manual Bit Socket: https://www.tien-i.com/category/1-socket-wrench-

Impact Bit Socket:https://www.tien-i.com/category/2-impact-socket-bits-sets