Used Honing Machines for Sale — 388

Honing is a low velocity finishing process performed by a specific tool called as the honing tool which contains a set of bonded abrasive sticks or stones. A common application of honing process is to finish the internal cylindrical surface. It also improves the form tolerance of the holes. Honing uses bonded abrasives just as in grinding while loosened abrasives are used in lapping & polishing. The point of contact during honing is not just a line as in grinding instead a complete area of the tool. In addition to the surface finish of about 0.1 µm, honing produces a characteristic crosshatched surface that tends to retain lubrication during operation of the component, thus contributing to its function and service life.

Honing Tool

The honing tool performs a combined rotary and reciprocating motion while the work piece does not perform any working motion. The point behind providing rotational and reciprocating movements is to give an uneven ratio and thus prevent an abrasive grain from ever traversing its own path twice. Also this type of a complex rotational and oscillatory axial motion of the hone is responsible for the crosshatched lay pattern of very low surface roughness. The abrasive sticks or stones are equally spaced about the periphery of the hone tool. The abrasives are held against the work surface with controlled light pressure usually exercised by small springs. The abrasive action of the honing tool removes material from the inside diameter of the part. A cutting fluid (honing oil) must be used in honing to cool and lubricate the tool and to help remove the chips. It also prevents pickup (spot welding of tool to bore) and loading (chips coating the stone).

Selection of Abrasives

For a required surface finish and material removal rate, the abrasive stones should be selected based on the flowing parameters: Type of abrasive, Grit size and Hardness. The four types of abrasives used are: Aluminium oxide, Silicon carbide, Cubic Boron Nitride (CBN) and Diamond. Among these, Aluminium oxide is the most commonly used abrasive in industrial applications. CBN and Diamond are used for very hard materials and are called super abrasives. Coarse grains are used for faster stock removal and fine grains are used when less material removal rate and fine finish are required. Coarse grains are used for ductile materials and fine grains are used for hard and brittle materials.

Types of Honing Machines: Vertical and Horizontal

There are two types of honing machines:

• Vertical Honing Machine
• Horizontal Honing Machine

Vertical honing machines hold the work piece and the honing tool with their axes in the vertical position while in horizontal honing machines both the work as well as the tool are held with their axes in horizontal direction. Vertical machines are suited for shorter jobs while horizontal machines are preferred for longer jobs. Part lengths up to 2000 mm are usually honed in vertical machines and jobs of more than 2000 mm length are honed in horizontal machines.

On TradeMachines, you have the possibility to find a wide choice of honing machines for sale, including sunnen honing machine, cylinder honing machine, portable honing machine, CNC honing machine, engine honing machine, etc.

Advantages and Disadvantages of Honing

The honing process offers advantages of low capital equipment cost, high metal removal rates, and extreme accuracy of 0.001mm in a wide variety of materials. It gives relatively high productivity when compared to a lapping machine. Several holes can be honed simultaneously on multiple spindle machines. Other advantages include the ability to create round and straight bores in relatively long work pieces, freedom from heat effects etc. It avoids surface damage due to heat as can occur with grinding operations. As there is no motion involved with the work piece, there are no chucks, faceplates, or rotating tables needed thereby eliminating chances of chucking or locating errors. The hone is driven from a central shaft, so bending of the shaft cannot cause tapered holes as it does when boring. The resultant crosshatch pattern of honing is very efficient in a moving bearing application such as an automotive cylinder bore honing tool or a valve body bore, since the peaks carry the load of the mating part and the valleys in the surface structure provides reservoirs for lubricating oil.

Honing machine process can be used to correct the following bore errors generated during the previous operations:

• Curvature
• Conicity
• Taper
• Waviness
• Undersize
• Lack of Roundness

Honing equipment can also correct parts that are not square, within limits. But the major constraint is that the part must have convenient clamping pads as work piece distortion during application of the process will not be caused. As the honing tool also gets worn out quickly, it should be sharpened from time to time for maintaining the quality of the products. Also the initial equipment cost is quite high when compared to other finishing processes. Hence, it is advisable to go for used honing machines for sale when cost restriction plays an important role.

Used Honing Machines for Sale

Here at Trademachines we can offer you some of the honing machines from manufacturers all over the  world : GEHRING Technologies, SUNNEN, ENGIS, CENTURY Machine, OSBORN, SOMOS International and OHIO Tool Works.