The plaintiff, who was in the employ of an independent contractor, was injured, while at work in the defendant’s *349factory, by reason of his clothing being caught upon a revolving set screw which projected about half an inch and held in place a collar upon a line of shafting. He testified that he never had seen this shafting when not in motion, and did not know of the existence of the set screw before the accident. There was evidence to show that the set screw looked dirty and greasy and was covered with lint and oil. There was further evidence to show that when the shafting was at rest the set screw was in plain sight, if one looked at it, and that it could be seen indistinctly when the shafting was in motion.
The duty which an owner owes to the employee of an independent contractor, is the duty owed by an employer to his employee in such a case. It follows that as to the plaintiff, who was lawfully at work in the defendant’s factory although he was at work for an independent contractor, the defendant owed him the same duty in relation to the permanent machinery and apparatus that it owed to its own employees.
The employee assumes all the obvious risks connected with his employment, but his contract does not contemplate the assumption of risks which are hidden and obscure. Accordingly, while the plaintiff was employed in the defendant’s factory the latter was bound to warn him only of hidden dangers which the plaintiff could not reasonably have discovered and which the defendant knew or ought to have known. Sullivan v. New Bedford Gas & Edison Light Co. 190 Mass. 288. Crimmins v. Booth, 202 Mass. 17.
The question then arises whether the presence of the set screw was or was not an obvious risk. In the numerous case's of this kind which have been passed upon by this court it generally has been held that the danger arising from a set screw was an obvious one which could have been discovered upon reasonable inspection.
The plaintiff contends that the case is to be distinguished from those wherein it has been held that there could be no recovery, because the plaintiff did not know of the existence of the set screw or that it was covered with grease and dirt and so could not be distinctly seen when in motion; and also because there was evidence to show that projecting set screws were not in common use in that locality.
*350If we assume that the evidence appeared to show that projecting set screws were not in common use, and that this one could not be seen when in motion, still we are of opinion that upon all the evidence the defendant is not liable. Archibald v. Cygolf Shoe Co. 186 Mass. 213. Ford v. Mount Tom Sulphite Pulp Co. 172 Mass. 544. McKenna v. Gould Wire Cord Co. 197 Mass. 406. Even if such a screw is not in common use in factories in the locality, yet its use was not unlawful and the defendant owed no duty to change the permanent equipment or kind of machinery in the factory then regularly and permanently used by it. Rooney v. Sewall & Day Cordage Co. 161 Mass. 153.
While the evidence in. the case at bar differs somewhat from that in previous cases, still we do not think it can be distinguished in principle. The plaintiff was a man of mature age and testified that the place where he was at work was light, and that if he had looked everything was in plain sight there; that he “had worked around shafting for six years and worked around it when it was going and had seen shafting work;” that he knew that couplings must be connected with the shafting, and that “a familiar, easy way of doing it would be to have a set screw there;” and although he received no warning about the shafting he testified that “We always looked out for it. Always looked out for the shafting. . . . We always use our own caution, — if it was anything near a pulley we always looked out for it.” While there was evidence to show that there was dirt, grease and oil on the set screw by reason of which it could not be seen distinctly when in motion, yet it is common knowledge that shafting and pulleys and their attachments, including set screws, necessarily must be more or less covered with dirt and oil when in use, and that such a condition is manifestly unavoidable. As was said by Knowlton, J., in Rooney v. Sewall & Day Cordage Co. 161 Mass. 153, 160: “Although the plaintiff says he did not know of the set screw, his testimony shows that he was well aware of the danger from the moving pulleys, belt, and shaft. ... He was more than forty years of age, and had had considerable experience. There is nothing in the case to indicate that he needed any warning of the danger from coming in contact with this rapidly revolving machinery, whether he knew of the set screw or not. Indeed, if the defendant had warned him, he would merely have been told *351that there was great danger of getting caught if he came in contact with that part of the machinery, and that he must use his best effort to avoid it. But it is evident that he knew all that without warning. It has been held in many similar cases that the accident was not imputable to negligence of the defendant.”
If we assume that the plaintiff was in the exercise of due care, and that the evidence admitted subject to the defendant’s exception was competent, it is plain that there was no evidence which would warrant a finding that the defendant was negligent. Mutter v. Lawrence Manuf. Co. 195 Mass. 517. Kennedy v. Merrimack Paving Co. 185 Mass. 442. Demers v. Marshall, 172 Mass. 548.
Judgment for the defendant.