Q: What is the definition of each product and what is the difference between them?

A: Pins, rollers, locating pins, needles and shafts are cylindrical mechanical parts. Although these products are different, the names can sometimes be used interchangeably.

Hartford Technologies manufactures all these parts or components in steel, stainless steel and other materials.

A "pin" is a mechanical fastener that connects other parts in an assembly. Pins can be used as pivots, hinges, clamps, clamps, or shafts. Fixture is usually used to fix the workpiece in place and/or guide the operation on the equipment. Pins are usually used to locate or fix parts. Some pins have heads; Others are not.

"Wheel" means that the part moves (rolls) when in use. Generally, the roller acts as a bearing, supporting the load along its outer diameter.

The "locating pin" is usually used in combination with the "pin" and can be used as a brake or closely aligned or supporting part. The brake prevents or prevents movement until it is released.

"Needle" or "needle roller" means that the length is significantly longer than the diameter. This part acts as a rolling element.

"Shaft" describes a complex cylindrical component or a slender part of a cylindrical part that has been turned or machined. Some customers use the term shaft to describe the basic components that most people will mark as pins or rollers.

Hartford Technologies produces pins, rollers, dowels, needles and shafts in a variety of configurations. We focus on precision and customized parts rather than commercial off-the-shelf parts.

Q: What are the most commonly used materials for pins, rollers, pins and needles?

Answer: Bearing grade chromium steel is often used for pins and rollers because of its excellent wear resistance, high hardness (usually Rockwell C 60 to 65) and strength. This steel is called 52100 (USA), 100Cr6 (Europe), SUJ2 (Japan) and GCr15 (China), all of which are essentially the same.

Stainless steel is used to improve corrosion protection. Martensitic 400 series stainless steel (the most common is 440) can also be heat treated to reach a high hardness level. Austenitic 300 series stainless steel (such as 302, 304, 316, etc.) has better corrosion resistance, but must be supplied (and thus processed) under harder conditions (if hardness is required), because it cannot be heat treated; The hardness can only be improved by cold working.

Other common pin and roller materials include low carbon steel (usually case-hardened) and high carbon steel (usually fully hardened). Precision pins and customized rollers are also made of other alloy steel (such as 4140, 4340, 8620, etc.) and special stainless steel (such as precipitation hardening stainless steel, such as 17-4PH, etc.).

Q: How are pins and rollers produced?

A: For bearing grade chrome steel parts, the raw materials of pins, rollers, pins and needles are usually supplied in the form of coils. The part is cut to approximate length. If the steel pin or roller only needs a small end radius or a broken edge, you can roll the part in the barrel to produce this situation.

This batch processing is very efficient. If the final configuration of the steel pin or roller has a large end radius or chamfer, you can add the feature in its basic form during the cutting process. In most cases, the end radius or chamfer of the steel pin or roller is added as a separate step.

Carry out centerless grinding process to make the part close to its final diameter. The parts are then heat treated, usually followed by quenching and tempering. According to the required diameter and length tolerances, perform one or more end grinding and centerless grinding operations to produce steel pins or rollers with the required accuracy. Generally, rolling (deburring) and polishing will complete the whole process.

A large number of tests are used in the manufacturing process to verify the quality of dimensions and processes. Pins and rollers usually need to meet high-precision dimensions and shapes.

For some customers and applications, special quality assurance is required. Hartford Technologies has a high-speed sorter that can perform 100% inspection of diameter and/or length. We also have a camera-based vision system that can perform 100% inspection on visual defects such as scratches, pits or discoloration.

Q: What are the specifications of pins and rollers?

Answer: The following is a list of some common steel pin and roller industry specifications:

·ASME B18.8.2 Dowel Pin

·ASTM F2443 needle roller, ball end

·ASTM F2511 Needle roller bearing roller

·DIN 5402 Part 1 Cylindrical rollers (parts of roller bearings)

·DIN 5402 Part 3 Rollers for needle roller bearings

·DIN 6325 dowel pin

·ISO 2338 parallel pins

·ISO 8734 dowel pin

Q: What are the common end configurations of pins and rollers?

A: The design of both ends of the steel pin or roller is usually selected after considering its function, assembly method and position. If there is no assembly problem, the most economical configuration is the small end radius. You can add this function in a simple batch bucket rollover step.

If steel pins or rollers are assembled into holes with small clearance or interference conditions, a larger end radius or chamfer will usually be selected. In this case, a separate processing process is required. In some parts, the end of the part performs functions (such as cams or pivots), so more specific geometry (such as spherical end pins) is required. Similarly, a separate turning process was added to create this function.

Q: Do all pins and rollers have a straight (constant diameter) outside diameter?

Answer: Although most steel pins and rollers are defined by the (constant) outside diameter with high accuracy (diameter tolerance ± 0.0001 inch/± 0.0025 mm), parts used as rolling elements in bearings are sometimes designed with crown diameter. For the crown outer diameter, the exact (constant) diameter is required along the central part of the steel roll length, but the diameter drop (taper) is specified for each end. This design can prevent higher stress at the end of the steel roll during its operation as a rolling bearing element. Generally, multiple grinding or superfinishing processes are used to obtain the coronal profile of the steel roll.