Thank you for your inquiry regarding this item from Prime-Line Products. Yes, this handle set should work just fine on a 1-3/4 in. thick door. The tailpiece of the thumbturn only needs to insert 50% of the door's thickness which would be 7/8 in. on a 1-3/4 in. door. When measuring the tailpiece of this thumbturn, from the underside of the plate to the tip of the thumblatch tailpiece it measures 1-1/16 in. in length.
For additional questions regarding this item, or any other product manufactured by Prime-Line Products, please call their toll free number at (877) 649-9740, or contact them by email at firstname.lastname@example.org