Wireline packing bore tolerance is ±0.001" to prevent grease bypass. Surface finish of 8–16 Ra minimizes wire wear and packing damage. Grease seal control heads incorporate hydraulic closing rams that squeeze the packing when wire is stationary, reducing grease loss during long logging runs. https://globalsealstech.com/product-category/oil-gas-seals/oil-free-lubricated-pump-seals/