3-3/8" apart.
The product number you have supplied is our screw in strainer. If you are using this as reference to what is existing for size and shape comparison, you would then have our snap in shower strainer. If you can slide something through the grate openings and pull up, the strainer will pop out.
Hi Stewart. Thank you for your question. The Plumbing Department may carry replacement screws for your Oatey 4 in. Round Universal Screw-in Shower Strainer in Stainless Steel, however, it may be a better choice to contact the manufacturer directly at: 800-321-9532 or go to their web site-www.oatey.com Please let us know if we can be of further assistance. Rick_HD_OC