A pin is an elongated tool with a certain length and diameter of the head portion. It is used to move and strike the cut-off slug to upset material and push it into the heading die. It is mostly used for the extraction (ejection) of finished fasteners from the press form of drawing equipment. Additionally, pins can also be used for forming, piercing, cutting, trimming, and other applications.

The knockout (or kickout) pin plays an important role in solid die heading. The pin acts as a blank support and also ejects finished parts. It is also called ejector, and can be made of solid carbide and high strength steel such as SKH9. Ejection pins application Knockout (or kickout) pins serve two functions.

  • Firstly, they stop blanks as they enter the die at the point where upsetting is to start. This requires them to be able to withstand some of the forming pressures.
  • Secondly, they eject the headed part from the die to clear it for the next blank. Pins must be manufactured to the exact required dimensions in order to ensure that they are able to perform their functions accurately and efficiently.

Ejection Pins Applications

The important factors in choosing pins should include the degree of corrosion resistance, durability, and tensile strength. Besides high-quality raw materials, we can offer plating and coating are two ways that can be applied to improve the life of the pins according to customers’ requests.

1. Ejector Pins

Also known as knockout pins, use these pins to push parts out of molds. Pins are precision-ground to tight tolerances and hardened for strength and wear resistance.

2. Shoulder-Style Ejector Pins

A thick shoulder underneath the head makes these pins more rigid than standard ejector pins. They’re precision-ground to tight tolerances and hardened for strength and wear resistance. Machining is not recommended.

3. Core Pins

Mold plastic around these pins to form small holes, or use them to perforate parts. They have a flat head to fit into a counterbored hole. Made of M2 tool steel, these pins are wear-resistant and stay sharp at high temperatures.

4. Flush-Mount Core Pins

A 60° beveled head fits into a countersunk hole. Mold plastic around these pins to form small holes, or use them to perforate parts. Also known as perforator, mold, forged, quill, and pilot pins, they can be machined to fit your application. Pins are precision-ground to tight tolerances. Made of M2 tool steel, these pins are wear-resistant and stay sharp at high temperatures.

5. Punch Pins

Use these pin blanks with a die to punch 1/8″ and larger holes. Made of M2 tool steel, these pins are wear-resistant and stay sharp at high temperatures. Heads are drawn to a Rockwell hardness of C45 to prevent breakage from shock.

Material-JIS Material-AISI Hardness (HRC) Features Applications
SKH-9 M2 61-64 SKH-9 steel is general-purpose high-speed steel with high wear resistance and toughness. Used for cold forging dies, punches, flat dies, punch pins, etc.
SKH-55 M35 63-66 SKH55   steel is tungsten molybdenum, vanadium-based high-speed tool steel with a   high toughness and high hardness, red hardness and wear resistance. Used for advanced screw dies etc.
ASP-30 M42 66-68 M42 is a molybdenum series high-speed steel alloy with a superior red hardness. Used for making high-heavy-load dies, pins of powdered high-speed steel/ stainless steel screws, and punches of hollow rivets.

Characteristics and properties of punch pins:

Type TiN (Titanium nitride) TiCN (Titanium carbide nitride) TiAlN (Titanium aluminum nitride) CrN (chromium nitride) WC/C ALCRONA
Hardness Hv2000 Hv3000 Hv3000~Hv5000 Hv1800 Hv1400 Hv3200
Surface roughness index (dry) 0.4 0.3~0.4 0.4 0.5 0.1 0.35
Layer thickness (microns) 2-4   um 2-4   um 2-5   um 3-6   um 1-4   um 2-4   um
Coating color gold gray dark purple silver black dark purple
Maximum working temperature 550℃ 400℃ 850-1000℃ 700℃ 300℃ 1100℃
Treatment temperature PVD 400-450℃ PVD 400-450℃ PVD 400-450℃ PVD 400℃ PVD 250℃ PVD 400-450℃

Benefit

  • Enhanced product quality: KO pins ensure that finished fasteners are extracted from the mold without any damage or deformation, resulting in higher quality products.
  • Longer mold lifespan: By reducing the risk of damage to molds during the extraction process, KO pins can help extend the lifespan of cold heading molds.
  • Cost savings: By increasing efficiency and reducing downtime, KO pins can help lower production costs and improve profitability for cold heading manufacturers.

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