Just 40 years before Large Size Billet/Blooms were cut by Chiesel and Hammer and small bars were cut by Shearing or Power Hacksaws. Bandsaw Machines were in use with Carbon Steel Blades with very poor cutting rate and repeated blade joint failure.
After the development of Bi-Metal HSS Bandsaw Blades having very strong back material allowed high tension/ stretching to offer excellent beam strength to cut very fast without taper and excellent tool life. Cutting rate on Bandsaw for medium alloy steel is around 40-50 sq cm per min as against all other old techniques where it was only 10-15 sq cm.
With the development of CNC machines and huge demand of components in Automobile Industries, all conventional machines were replaced with CNC Machines. To feed each CNC machine average 5 bandsaws were needed to provide cut pieces to run the plant with full capacity. With the installation of CNC machines Bandsaw demand increased which required huge expensive space, hence many vendors came up for cutting of the bars, and this arrangement continued for 8-10 years.
Japan based TCT saw manufacturers developed Throw away Cermet Thin Kerf TCT Circular Saw Blade of 2 mm thickness which were very fast in cutting. To use such blades NC Circular Sawing Machines were introduced in Japan by NISHIMAX, TSUNE, AMADA machine manufacturers with great success but were very expensive. Later on in 2000-2002 some Taiwanese companies introduced similar Machines at half price. In 2004-2006 Indian manufacturers introduced similar application machines with many modifications at 25% price to suit India conditions of Raw material and minimum per cut cost.
Initially, per cut tool cost of Bars upto 80 mm was around 6 NP (INR0.06) per sq cm as against 4 NP on Bandsaw Machines. High per cut cost was great concern for the Indian NC Circular Sawing machine manufacturer as people were reluctant in investing in such machines.
Leading and Pioneer Indian designer/ manufacturer of these machines invested huge time & money in research and development to optimise tool life to bring down tool cost. In 2008, tool cost reduced to 3NP/sq cm from 6 NP which attracted many users of Bandsaws to NC Carbide Circular Sawing Machines. This way 5 bandsaws were replaced by one Circular Sawing Machine
which reduced expensive floor space, man power, rejection and maintenance issues. Also material yield increased as cutting allowance were reduced substantially because of quality cut and close length tolerance on cut piece.
Now Bar cutting upto 200 mm is viable to cut on Circular Sawing Machines. Various Indian made models are available from 50, 80, 110, 130, 160, 175 and 200 mm Round Bar cutting capacity to suit individual’s requirements.
Continuous efforts are being put to bring down tool cost to save on Foreign Exchange as well as secure Carbon Credits by resharpening of TCT saw blades which requires huge investment in CNC re- sharpening Machines. In collaboration with the Japanese Saw Blade Manufacturer a reconditioning centre has been established in Indore MP. After resharpening, per cut tool cost reduces to 50% as 3-4 resharpening is possible of TCT saw Blades.
NC Circular Sawing Machines are gift to cut Stainless Steel, Bearing Steel, Super Alloy and other exotic material with great success.