| Name and Model Number | Keuffel and Esser 8858 Loaner Slide Rule |
| Country of Origin | USA |
| Date of Manufacture | c. 1941 |
| Front Scales | A [ B C] D |
| Back Scales | [S L T ] |
| Scale Length | 25 cm |
| Type of Rule | Slide Rule |
| Construction | Printed scales on white painted boxwood or pearwood |
| Area of Use | Generic |
| Comment | Was loaned to customers during WWII for a $1 deposit.
See image of back of rule. |
| Rarity | RR |
| Donor | Collection of Clay Castleberry |
| Match Number | 252 |
| Thumbnail (Click Picture for Details) |  |
| In conjunction with our 'donors' we assign a rarity rating to each item, based on the system devised by Herman van Herwijnen |
| (1929 - 2004), renowned Dutch collector, author, and creator of Herman's Archive, a collection of 5,000 slide rule images on CD. |
| • RR = Rare - 1 of 25 collectors has one; it may take a year to find an example in the marketplace. |
| • RRR = Very Rare - only a few known to collectors; may be several years before it comes up for sale. |
| • RRRR = Extremely Rare - a museum piece; unlikely that an example will come up for sale. |