Agency refers to Rural Utilities Service (RUS), United States Department of Agriculture.
Certificate of compliance is a written certification by an authorized employee of the producer that the material shipped meets the requirements of this specification and any supplemental requirements specified in a purchase order from a borrower or the borrower's contractor.
Crossarm refers to the structural wood member used to support electrical conductors and equipment. The word arm is used interchangeably with crossarm.
Independent inspection refers to examination of material by a trained inspector employed by a commercial inspection agency.
Inspection means an examination of material in sufficient detail to ensure conformity to all requirements of the specification under which it was purchased.
Lot is a certain number of pieces of a given item submitted for inspection at one time.
Producer is the party who manufactures arms. In some cases the producer may also be the treating plant.
Purchaser refers to either the RUS borrower or contractors acting as the borrower's agent, except where a part of the specification in this section specifically refers to only the borrower or the contractor.
Quality control supervisor refers to an employee of the producer designated to be responsible for quality control procedures carried out by said producer.
Reserve treated stock consists of treated material held in storage by a producer for purchase and immediate shipment to a borrower.
Supplier may refer to the producer, the treater, or to a third-party broker or distributorship involved in supplying RUS products to the borrowers.
Treating plant is the facility that applies the preservative treatment to the arms.
Table 1 to Paragraph (d)(3)(ii)-Knot Limits for Distribution Arms (See Figure 1 to This Section)
[All dimensions in inches]
Class of knot and location | Maximum knot diameter | |
Close grain | Dense grain | |
Round Knots: | ||
Single Knot: Maximum Diameter Center Section1 | ||
Upper Half | 3/4 | 1 |
Lower Half | 1 | 11/4 |
Elsewhere | 11/4 | 11/2 |
Sum of Diameters in 6-Inch Length: Maximum Center Section: | ||
Upper Half | 11/2 | 2 |
Lower Half | 2 | 21/2 |
Elsewhere | 21/2 | 3 |
1 No knot shall be closer than its diameter to the pole mounting hole.
Table 2 to Paragraph (d)(3)(ii)-Knot Limits for Transmission Arms (See Figure 2 to This Section)
[All dimensions in inches]
Pole mounting hole zone1 | Maximum diameter for single knot |
Upper Half (inner zone) | 3/4. |
Upper Half (outer zone) | 1 for close grain. |
11/4 dense grain. |
Other locations transmission arm size2 | Narrow face | Wide face (two sides) | |
Edge | Along centerline | ||
45/8 * 55/8 or less | 1 | 11/4 | 11/4 |
55/8 * 73/8 | 11/4 | 13/8 | 17/8 |
35/8 * 93/8 | 3/4 | 13/4 | 21/4 |
1 No knot shall be closer than its diameter to the pole mounting hole.
2 For cross sections not shown, refer to grading rules.
Max. time (hours) | Temperature | |
(i) Steam | 3 | 220 °F |
(ii) Heating in Preservative | 3 | 210 °F |
Preservative | Retention (pcf) |
(i) Creosote | 8.0 |
(ii) Pentachlorophenol | 1 0.4/0.36 |
(iii) ACA, ACZA, or CCA-C | 0.4 |
(iv) Copper Naphthenate | 0.04 |
(v) DCOI | 0.13 |
1 If the copper pyridine method is used when timbers may have been in contact with salt water, a penta retention of 0.36 pcf is required for all species native to the Pacific Coast region.
7 C.F.R. §1728.201