Prosecution Insights
Last updated: April 19, 2026
Application No. 18/511,704

TWIST DRILL WITH MULTI-STEP DRILL POINT

Non-Final OA §103
Filed
Nov 16, 2023
Examiner
COOK, KYLE A
Art Unit
3726
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Danyang Kaiyiyuan Tools Co. Ltd.
OA Round
1 (Non-Final)
62%
Grant Probability
Moderate
1-2
OA Rounds
2y 10m
To Grant
99%
With Interview

Examiner Intelligence

Grants 62% of resolved cases
62%
Career Allow Rate
172 granted / 277 resolved
-7.9% vs TC avg
Strong +41% interview lift
Without
With
+40.7%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
49 currently pending
Career history
326
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
70.6%
+30.6% vs TC avg
§102
4.5%
-35.5% vs TC avg
§112
18.9%
-21.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 277 resolved cases

Office Action

§103
Detailed Action1 America Invents Act Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . In the event the determination of the status of the application as subject to AIA 35 USC 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. Rejections under 35 USC 1032 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102 of this title, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious3 before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103(a) are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claims 1-3 are rejected under 35 U.S.C. 103 as being unpatentable over CN-214720850-U (“Wang”) in view of USPGPub No. 2020/0094331 (“the ‘331 reference”). Regarding claim 1, Wang teaches a twist drill with a multi-step drill point (figs. 1-2, ¶ [0002), wherein all references to the Wang specification refer to USPGPub No. 2022/0362863 which is the English publication of Wang), comprising: a shank (1); and a cutting portion (2); wherein the cutting portion is provided with a spiral flute (3) and a body clearance (4) (fig. 1, ¶ [0024]); a tip of the cutting portion is provided with a chisel edge (6) and a cutting edge (5), and a flank face (7) connected with the cutting edge is provided with a stepped groove (8); the stepped groove is configured to divide the cutting edge into several sections (figs. 1-2, ¶ [0024]-[0025]). Wang teaches the cutting groove having a varying pitch that increases from the tip towards the shank (¶ [0028]-[0030]). Thus, Wang fails to explicitly teach a pitch of the stepped groove is configured to decrease along a direction from the tip of the cutting portion to the shank. However, this would have been obvious in view of the ‘331 reference. The ‘331 reference is also directed to a twist drill with a multi-step drill point and a spiral stepped groove (fig. 3, ¶ [0006]-[0007]). The ‘331 reference teaches the pitch of the stepped groove can increase, decrease, or remain equal depending on the required type and property of drilling (¶ [0069]). In this case, each of Wang and the ‘331 reference teach a twist drill with a multi-step drill point and a spiral stepped groove. While Wang teaches a pitch of the stepped groove increasing from the tip of the drill, the ‘331 reference teaches one of skill in the art that the pitch can also decrease depending on the type of drilling. Thus, in order to provide a drill optimized for other types of drilling, it would be obvious to modify Wang so that the pitch of the stepped groove decreases from the tip toward the shank. Regarding claim 2, Wang further teaches the stepped groove is in a spiral shape; a spiral direction of the stepped groove is the same as a spiral direction of the spiral flute (figs. 1-2, ¶ [0024]). Claim 2 also recites a slope of the stepped groove is configured to decrease along the direction from the tip of the cutting portion to the shank. In view of Applicant’s disclosure, slope is interpreted as the angle between a line orthogonal to the longitudinal axis of the drill and the direction the stepped groove extends around the circumference of the drill. One of skill in the art appreciates that the slope of the stepped groove is related to the pitch of stepped groove and diameter of the drill bit, wherein for a constant or increasing diameter a decreasing pitch will result in a decreasing slope of the stepped groove (since decreased slope will reduce the axial length it takes for the stepped groove to make one full rotation). In this case, Wang et al. teaches a decreasing pitch from the tip towards the shank and an increasing diameter from the tip towards the shank. Thus, the slope of the stepped groove with respect to a line orthogonal to the longitudinal axis of the drill will decrease in order to provide the decreasing pitch. Claim 3 recites a decreasing range of the slope of the stepped groove is 17°-8°. MPEP 2144.05(II) states that where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. In this case, Wang et al. teach a decreasing slope of the stepped groove to provide a decreasing pitch from the tip towards the shank. While Wang et al. is silent as to specific pitch lengths (or the rate the pitch decreases), which is directly related to the slope and rate of change of the slope of the stepped groove, determining a range of workable pitches for the drill of Wang et al. can be found by routine experimentation since changing the pitches and determining the effects of the different pitches can quickly and easily be done with a software program. Thus, it would be routine experimentation to determine a range of pitches for each step of the drill that results in a range of slopes of the stepped groove (over at least a portion of the length of the drill) of between 17-8 degrees. Claims 1-3 rejected under 35 U.S.C. 103 as being unpatentable over the ‘331 reference in view of Wang. Regarding claim 1, the ‘331 reference teaches a twist drill with a multi-step drill point (fig. 3, ¶ [0006]-[0007]), comprising: a shank (2); and a cutting portion (1) (figs. 3 & 7, ¶ [0043]-[0044]); wherein the cutting portion is provided with a spiral flute (IV); a tip of the cutting portion is provided with a chisel edge (VII) and a cutting edge (VIII & 153) (figs. 3-4, ¶ [0045]), and a flank face (147) connected with the cutting edge is provided with a stepped groove (145) (figs. 3-5, ¶ [0050]-[0051]); the stepped groove is configured to divide the cutting edge into several sections (figs. 3-5, ¶ [0050]-[0051] & [0067]-[0069], i.e. the several sections being the different sections/surfaces of cutting edges or the different steps having varying diameters and pitches); and a pitch of the stepped groove is configured to decrease along a direction from the tip of the cutting portion to the shank (¶ [0069]). The ‘331 reference fails to explicitly teach the cutting portion provided with a body clearance. However, body clearances are well known in twist drills to reduce friction. Wang also teaches that it is known to have multi-step twist drills that also have body clearance (fig. 1, ¶ [0024]). Thus, in order to reduce friction, it would be obvious to provide the cutting portion of the drill of the ‘331 reference with a body clearance. Regarding claim 2, the ‘331 reference further teaches the stepped groove is in a spiral shape; a spiral direction of the stepped groove is the same as a spiral direction of the spiral flute (fig. 3, ¶ [0048]-[0050]). Claim 2 also recites a slope of the stepped groove is configured to decrease along the direction from the tip of the cutting portion to the shank. One of skill in the art appreciates that the slope of the stepped groove is related to the pitch of stepped groove and diameter of the drill bit, wherein for a constant or increasing diameter a decreasing pitch will result in a decreasing slope of the stepped groove (since decreased slope will reduce the axial length it takes for the stepped groove to make one full rotation). In this case, the ‘331 reference teaches a decreasing pitch from the tip towards the shank and an increasing diameter from the tip towards the shank. Thus, the slope of the stepped groove with respect to a line orthogonal to the longitudinal axis of the drill will decrease in order to provide the decreasing pitch. Claim 3 recites a decreasing range of the slope of the stepped groove is 17°-8°. MPEP 2144.05(II) states that where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. In this case, the ‘311 reference teaches a decreasing slope of the stepped groove to provide a decreasing pitch from the tip towards the shank. While the ‘311 reference is silent as to specific pitch lengths (or the rate the pitch decreases), which is directly related to the slope and rate of change of the slope of the stepped groove, determining a range of workable pitches for the drill of the ‘311 reference can be found by routine experimentation since changing the pitches and determining the effects of the different pitches can quickly and easily be done with a software program. Thus, it would be routine experimentation to determine a range of pitches for each step of the drill that results in a range of slopes of the stepped groove (over at least a portion of the length of the drill) of between 17-8 degrees. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Kyle Cook whose telephone number is 571-272-2281. The examiner’s fax number is 571-273-3545. The examiner can normally be reached on Monday-Friday 9AM-5PM EST. If attempts to reach the examiner by telephone are unsuccessful, please contact the examiner's supervisor Thomas Hong (571-272-0993). The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://portal.uspto.gov/external/portal. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). /KYLE A COOK/Primary Examiner, Art Unit 3726 1 The following conventions are used in this office action. All direct quotations from claims are presented in italics. All information within non-italicized parentheses and presented with claim language are from or refer to the cited prior art reference unless explicitly stated otherwise. 2 In 103 rejections, when the primary reference is followed by “et al.”, “et al.” refers to the secondary references. For example, if Jones was modified by Smith and Johnson, subsequent recitations of “Jones et al.” mean “Jones in view of Smith and Johnson”. 3 Hereafter all uses of the word “obvious” should be construed to mean “obvious to one of ordinary skill in the art before the effective filing date of the claimed invention.”
Read full office action

Prosecution Timeline

Nov 16, 2023
Application Filed
Feb 12, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
62%
Grant Probability
99%
With Interview (+40.7%)
2y 10m
Median Time to Grant
Low
PTA Risk
Based on 277 resolved cases by this examiner. Grant probability derived from career allow rate.

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