Table 3: The range of feed rates used by researchers for studying R_a in the hard turning.

Reference	Type of insert	Material	Feed rate range (mm/rev)
[Lalwani et al.]	Coated Ceramic	MDN250	0.04-0.12
[Ding et al.]	CBN	AISI 52100	0.05-0.12
[Agrawal et al.]	CBN	AISI 4340	0.08-0.15
[Singh et al.]	Ceramic	AISI 52100	0.1-0.32
[Akkuş et al.]	Coated carbide	AISI 4140	0.18-0.36
[Asiltürk et al.]	Coated carbide	AISI 4140	0.18-0.36
[Elbah et al.]	Wiper and conventional Ceramic	AISI 4140	0.08-0.14
[Kiran et al.]	Coated carbide	ST 174PH, ST 12TE, ST T1/13W	0.08-0.24
[Singh et al.]	Ceramic	AISI 52100	0.1-0.32
[Özel et al.]	CBN	AISI H13	0.1-0.2
[Khrais et al.]	Cemented carbide	AISI 4140	0.14 (constant)
[Das et al.]	Coated Ceramic	AISI 4140	0.05-0.15
[Aslan et al.] [Ferreira et al.]	Coated Ceramic Coated Ceramic	AISI 4140 AISI H13	0.05-0.2 0.05-0.4
[Aouici et al.]	CBN	X38CrMoV5-1 steel	0.08-0.16
[Kumar et al.]	Ceramic	EN 24 steel	0.12 (constant)
[Liu et al.]	CBN	JIS SUJ2	0.1 (constant)
[Revel et al.]	CBN	AISI 52100	0.05-0.1
[Sharman et al.]	Coated tungsten carbide	Inconel 718TM	0.25-0.5
[Huang et al.]	CBN	52100 bearing steel	0.07-0.15
[Ahmari et al.]	Carbide	AISI 302	0.1-0.3
[Lima et al.]	Coated carbide	AISI 4340, AISI D2	0.1-0.3
[Chou et al.]	CBN	AISI 52100	0.01 (constant)
[Aouici et al.]	CBN	AISI H11 steel	0.08-0.16
[Çydaş et al.]	CBN, Carbide, Ceramic	AISI 4340	0.08-0.24
[Çydaş et al.]	Coated carbide	AISI 4340	0.1-0.26
[Çydaş et al.]	Ceramic	AISI D2	0.05-0.15
[Çydaş et al.] [Dogra et al.] [Mondal et al.] [Qin et al.] [Qin et al.]	CBN            CBN           TiC coated carbide            PCBN            CBN	EN 31           AISI 8620 steel            16MnCrS5            40Cr steel AISI 1053 - AISI 1070	0.075-0.15           0.08 0.06-0.1           0.08            -