Swanson Mechanical Carpenter Pencil Refill Leads are sharp on both sides. The lead will also last 5 times longer since there is no waste due to sharpening. See here for the Swanson Mechanical Carpenter Pencil.
Product Model # Swanson Mechanical Carpenter Pencil Refills - 24 Pack CPLBLK
For California Residents:
WARNING: Cancer & Reproductive Harm - www.P65Warnings.ca.gov
WARNING: Drilling, sawing, sanding or machining wood products can expose you to wood dust, a substance known to the State of California to cause cancer. Avoid inhaling wood dust or use a dust mask or other safeguards for personal protection. For more information go to www.P65Warnings.ca.gov/wood