Hatch Distance and Scan Distance
Scan spacing


  Within each of the ‘islands’, simple alternating scan vectors are used with the spacing between these vectors defined as the ‘scan spacing’ and the speed with which the laser spot moves across the surface defined as the ‘scan speed’. 




Source


The influence of the laser scan strategy on grain structure and cracking behaviour in SLM powder-bed fabricated nickel superalloy
chapter: 2.2. SLM processing and laser scan strategy


Hatch distance


  The stripe pattern is a band defined by the scan vector width (ie stripe width), the hatching space between adjacent tracks and the scan direction as well as the overlap with the neighbouring stripes





Source 


Scanning patterns in SLM


Notes


The computer controlled laser scans the surface of the bed to selectively melt the current two-dimensional slice of the CAD file.
The laser scanning remelts some of the previously built layer to ensure good bonding between layers and a fully dense component overall.
Cool printing image