A tunneling machine includes a support frame, a rotatable cutter head, and inside roller cutters and gage roller cutters for cutting or crushing the end face of a tunnel. Each gage cutter has a gage scraper with a scraper blade engaging the tunnel surface for clearing materials from the path of the gage cutter. A spring biases the scraper blade toward the tunnel surface, and the scraper blade is pivotally mounted with respect to the cutter head for movement toward and away from the tunnel surface along an arcuate path. A bolt head in the arcuate path provides an adjustable stop for preventing excessive outward travel of the scraper blade when a void is encountered in the tunnel surface. The bolt also provides a release means to displace the scraper blade away from the tunnel surface to permit removal of the scraper blade.