1822 T. Tredgold Pract. Ess. Strength of Cast Iron ii. 24 The second table..is intended to show the greatest weight a beam of cast iron will bear in the middle of its length, when it is loaded with as much as it will bear, so as to recover its natural form when the load is removed. If a beam be loaded beyond that point, the equilibrium of its parts is destroyed, and it takes a permanent set.

a1898 H. Bessemer Autobiogr. (1905) xii. 161 Semi-steel..possesses..much greater tensile strength than soft iron. It is also more elastic, and does not readily take a permanent set.

1947 J. M. Edwards in P. I. Smith Pract. Plastics ix. 130/2 Typical time deformation graphs for phenol formaldehyde resin laminated material are given in Fig. 15; creep, cold flow, recovery and permanent set are illustrated.

1963 R. R. A. Higham Handbk. Papermaking ii. 36 The hornified cellulose fibres are not capable of assuming their original shape because of the permanent set that has taken place in the structural walls of the fibres.

1999 R. German World of Rubber 26 Rubber has many more properties including..how much it will permanently change its shape under prolonged stress (permanent set).

1853 J. Laurie Elem. Homoeopathic Pract. Physic 226 The first set, called the milk teeth,..are smaller and narrower than those of the permanent set.

1898 B. P. Colton Physiol. vii. 201 The thirty-two teeth of the permanent set were preceded by a temporary set of twenty Milk Teeth.

a1933 J. A. Thomson Biol. for Everyman (1934) I. xxi. 660 With few exceptions there are teeth, fixed in sockets, and usually in two sets—a short-lived ‘milk set’ and a permanent set.

1999 Providence Jrnl.-Bull. (Rhode Island) (Nexis) 9 Nov. 5 b A children's crusade. Expect to hear a lot of opinions coming from little people still waiting for their permanent set of teeth.