Shear banded chip formation typically occurs at frequencies between 1 kHz and 100 kHz, accompanied by large cyclic changes in cutting force, contact length and stress distribution near the tool tip. These changes are related to the mechanical properties of the work material being cut, under the large strain, strain rate and temperature conditions that exist in and around these shear bands. This study is aimed at experimental measurement of the dynamic changes in stress distribution within the cutting tool and to measure the cyclic variation in contact stresses along the tool rake face. Orthogonal end turning of AA-7075-T6 tubular specimens is carried out with a transparent birefringent sapphire plate as the cutting tool. Machining is done at high feed to produce shear banded chips exhibiting a shear banding frequency of 8 to 9 kHz, as inferred from measured cutting forces and chip morphology. A Photron Crysta® high-speed polarization measuring camera system with high magnification optics is used to obtain transmission photoelasticity videos of the tool tip region at 60 kHz. The videos record pixel-wise changes in the plane of polarization of the light transmitted through the highly stressed tool-tip region, from which the principal stresses as well as the principal stress directions are calculated. The high frame rate has helped resolve cyclic variations in tool stresses within individual shear banding cycles. Quantitative analysis of the images using the shear difference method is carried out to yield the distribution of normal and shear stresses over the rake face-chip contact. © 2024