You can use this k factor calculator to calculate k factor using reverse engineering method.
													
																	Sheet metal k factor formula. 
								
	
		
	
																	This change in sheet length depends on the position of neutral axis or k factor. 
																	Cad tools use k factor to calculate sheet metal blank. 
																	K factor a constant determined by dividing the thickness of the sheet by the location of the neutral axis which is the part of sheet metal that does not change length. 
																	The k factor is the most important and elusive variable of bending because it varies both as a function of the material and according to parameters such as angle and tooling. 
															
													
								
	
		
	
																	Mathematically k factor value is equal to the ratio of position of neutral axis and sheet thickness. 
																	K factor in sheet metal bending is a constant used to calculate sheet metal flat length or flat pattern. 
																	The k factor formulation does not take the forming stresses into account but is simply a geometric calculation of the location of the neutral line after the forces are applied and is thus the roll up of all the unknown error factors for a given setup. 
																	Calculate k factor bend allowance and y factor for sheet metal bending. 
															
													
								
	
		
	
																	The part of the material that bends. 
																	As a result overall sheet length increases. 
																	For our example it comes to. 
																	Plug the bend allowance ba the bend angle b inside radius ir and material thickness mt into the below equation to determine the k factor k. 
															
													
								
	
		
	
																	4 1 893 2 214. 
																	Best way to calculate k factor in sheet metal is by reverse engineering. 
																	The k factor is defined as the ratio between the material thickness t and the neutral fibre axis t i e.