I purchased one of your Amtech oscillating corded tools. After using it on my new house for 4 weeks. I seem to have lost the 5mm hex screw and washer to allow for the attachments to be secured. Work on my house has stopped! Because I was using it for everything, brilliant tool. However, I can’t see anywhere to buy the 5mm screw and washer, could you advise me where to buy please??