No it's not extendable.
No, it can't be used as chair leg replacements.
we do not carry any legs that length that are recommended for cabinets
Hello Farve, Thank you for your recent inquiry with The Home Depot. Unfortunately, we do not stock this Parsons Table Leg in a 40" length. I was unable to find a 40" desk leg on our website. For any other questions, please call us at HomeDepot.com Customer Service 800-430-3376. Thank you for shopping Home Depot.
no drill bit installation hardware
Hi MaryBeth, we do offer a Waddell Heavy Duty Top Plate that is frequently purchased with this 15 in. Parsons Table Leg on Homedepot.com that may suit your needs. Please review the product details to see if the product will work for your project. Model # 2755 Internet #100390125 Store SKU #779225 We appreciate your business and look forward to serving you in the future. Thank you for shopping Home Depot!