Check the listing for details. Acorn Hex Cap Nuts Stainless Steel Standard Height. Condition: New. Listed at 7.50 USD. Acorn nut is its common name and it is also called a crown hex nut, blind nut, cap nut or domed cap nut. It is a nut that has a domed top to cover the threads.This is to prevent contact with the external thread to protect the threads or protect other things the threads would rub against. In addition the dome gives a more finished appearance.nuts and bolts. General Product Information Size Drive Size Overall Height Internal Thread Depth 4-40 1/4" 1/4" 0.159" 6-32 5/16" 11/32" 0.204" 8-32 5/16" 11/32" 0.229" 10-24 3/8" 13/32" 0.280" 10-32 3/8" 13/32" 0.280" 12-24 3/8" 13/32" 0.350" 1/4-20 7/16" 15/32" 0.350" 1/4-28 7/16" 15/32" 0.350" 5/16-18 1/2" 17/32" 0.410" 5/16-24 1/2" 17/32" 0.410" 3/8-16 9/16" 5/8" 0.450" 3/8-24 9/16" 5/8" 0.450" 7/16-14 5/8" 11/16" 0.480" 1/2-13 3/4" 13/16" 0.590" 1/2-20 3/4" 13/16" 0.590" 5/8-11 15/16" 1" 0.750" 34-10 1-1/16" 1-5/32" 0.880" Shipping: All orders placed before 3:30 pm EST Will Ship Same Day Tracking is provided on ALL Orders Priority Mail Shipping service is offered at a discount of only $3.95 UPS Ground UPS Next Day Air is available, Please inquire for pricing Returns : ALL returns are accepted if returned within 60 days. Money Back or exchange guaranteed. NO Restocking Fees. For YOU, we constantly strive to find ways to improve our performance.