Scratch tests were done on thermally resistant hard Si-C-N coatings developed on glass substrates using magnetron sputtering. The change in loading rate and coating thickness showed variation in adhesion strength and wear, The Boussinesq, Hans and Blister stress distribution beneath the indenter had on effect of the failure processes. Elastic recovery was prevalent in coatings of higher thickness and higher rate of loading. The increased loading rate although caused early failure but resulted in less wear.