risers 48 which are attached in a suitable fashion to stringers 50 51 which support the stair for purposes of the following description the detailed construction of only one of the stringers of the apparatus of the present invention will be described further although a stair with two stringers is shown it will be apparent that many stairs are constructed against a wall so that only one stringer would have a guardrail furthermore although the stairs shown have risers as noted above in the case of pan stairs there are no risers as can be seen in fig4 the stringers 50 52 act as side supports for the stair and are generally at the desired pitch of the stairs stringer 50 comprises a channel shaped metal beam having a main beam portion 52 and spaced laterally extending flanges 54 and 56 as can be seen in fig5 flanges 54 and 56 space beam portion 52 from stanchion 12 it will be appreciated that the stringer 50 need not be channel shaped but could be a square tubular member a wooden beam etc but in any event would have a surface 58 spaced from stanchion 12 as can be seen in fig5 stringer 50 is received between first and second jaw assemblies 20 and 22 such that flange portion 24 abuts the side 58 of stringer beam portion 54 adjacent flange portion 56 further when so positioned it can be seen that by tightening wing nuts 32 and 44 flanges 24 and 36 respectively will urge stanchion 12 toward stringer 50 stanchion 12 being compressed against the outer edges of flanges.